Faint light is starting to filter through the trees at the Trinity Cemetery in the German city of Dresden, where two undertakers, part way through an exhumation, are driving their shovels into the soil.

Karin Ranisch, her husband Bernd and their three adult daughters look on in tense anticipation. For the grave belongs to the family's firstborn, Christoph, who was pronounced dead at a Dresden hospital in June, 1975. He was just two years old.

Back then, the city was still part of the former communist German Democratic Republic (GDR), in which the secret police known as the Stasi went to extraordinary lengths — including infiltrating families through spying — to keep the population in check.

"We grew up with the system, with the idea that you believed everything you were told," Karin Ranisch told DW. "Of course there was a lot you didn't believe, but you couldn't work against the system."

One thing she has never been able to believe is the story of her young son's death.

"You have a mother's sense," Karin said. "I've always thought it, but didn't tell anyone about it because they'd think I was crazy."

On the radar?

The family ran a tailoring business in Dresden, and before the Berlin Wall went up in 1961, Karin's sister fled to West Germany. They were wary of speaking about the family connection, knowing that voicing critical opinion or failing to demonstrate loyalty to the regime could result in persecution or imprisonment, or lead to parents being separated from their children.

Ivonne Ranisch, the eldest of the three daughters, who now lives in Australia, believes her family was on the authorities' radar.

"We were not a very conforming family, my parents were running their own business, which was something that was not looked upon very well," she said. "So you didn't work for the state, you worked for yourself."

Read more: Understanding East Germany: A never-ending look at the past

The day everything changed

Nonetheless, Karin kept a low profile, and managed to lead a largely normal life. Two years after she married Bernd, Christoph was born.

"We wanted a baby and it was so lovely with him," she says. Until the morning of Sunday, June 22, 1975. They were at the family holiday house on the outskirts of the city and Christoph's grandmother wanted to boil some water.

"At the time, you just had a heating element which you put in the water," Ivonne told DW. "It was cord which you attached to the wall to heat it."

When Christoph pulled on it, the boiling water tipped all over him.

"It went on the front of his body, and his thighs," Katrin recalls. "I tore his clothes off straight away because I knew I should stop fibers from getting into the wound."

They had no phone and no car, so holding Christoph, Karin rushed onto the street outside to find someone to call the hospital. The ambulance arrived soon after.

"I asked them if it was life-threatening and they said: 'No, we've seen children in worse conditions than this pull through.'"

He was taken to what is now the Dresden University clinic, where he was bandaged in sterilized dressings and where Karin was again told his injuries were not fatal and that he would be fine. With that information, she was sent home.

"We were allowed to call up at eight in the evening to check how he was," she remembers. "They said that under the circumstance, he was doing well."

Horrific news

But the following morning, they received a telegram telling them to go to the hospital straight away. Nothing could have prepared the young parents for the news that awaited them. Nor for the way it was delivered.

"It was so terrible how heartless the doctors dealt with us, they had no feeling, nothing. It was just brutal how they told us: 'your child is dead,' and that was that."

When Karin and her husband asked to see his body, they were told they couldn't.

"They said: 'He's not here, he's not in the clinic anymore, he's already in forensics,'" Karin remembers.

The following day, she went back and asked to see her son's body, but again, she was refused permission.

"You're in such a state of shock that you're not capable of questioning them further," Karin says. "We were completely helpless."

Read more: GDR's victims continue fight for justice and recognition

No questions allowed

Karin and her husband never saw their little boy again. Not even at the funeral. Although they were allowed to provide clothes for Christoph's burial, the coffin was sealed shut.

It was this refusal to let them see the body, coupled with the emergence of two death certificates citing different causes of death — scalding and pulmonary aspiration, respectively — and that they had previously been told he was conscious and doing fine that planted doubts in Karin's mind.

"I've had this sense all my life that he's not dead, that he's alive somewhere," she said. "I always had the feeling that it cannot be, there were so many inconsistencies."

But because of the way East Germany was run, she says she had no rights and couldn't ask questions of the hospital or the authorities.

"The doctors were the gods in white, you never ever questioned them, everything they said was right," Ivonne said. "There was a lot of fear. If you didn't conform, something might have happened to you."

Read more: Berlin and Beyond: Moving to East Germany

Moving to the West

Ivonne was born a year after Christoph's accident, and identical twin girls, Doreen and Christin, followed. In the mid-1980s, the family applied for an exit visa and was granted permission to move to Hamburg in West Germany. Even there, Karin was never able to shake her suspicions, but still she kept them to herself.

It wasn't until 1990, after the fall of the Berlin Wall, that she decided to act on them. She found a pretext to travel back to the former East to try and access old records that might tell her what had happened to Christoph. A family friend had put her in touch with a public medical officer, but this contact told her she wouldn't find anything in the documents and that she had three daughters and should just let it go.

"And then I did really let it rest, but in hindsight, she simply persuaded me to do nothing," Karin says.

That era of doing nothing is now over. When other parents started speaking publicly about how they believe their babies, declared dead in East German hospitals, may still be alive somewhere, she finally decided to tell her family about the doubts she had repressed for so long.

"My mum started really talking about it, only recently in January 2018, she said 'I really don't believe he's dead.' And I said to her, 'we have to do something about this...'" Ivonne said. "It was a real shock, I never thought of this possibility."

Thousands of disappearances

Ivonne started doing some research, and came across a group called Die Gestohlenen Kinder der DDR, or the Stolen Children of the GDR. Founded in 2014, it now has about 1,750 members, some 600 of whom are personally affected by missing children.

Of those, around a third are looking for children taken from parents deemed politically unfit and adopted by families loyal to the regime in the '70s and '80s. It remains a largely unexplored chapter of German history. Estimates of the number of such cases range from hundreds to the low thousands.

The other two-thirds of the group's members experienced situations that echo Ranisch's. Many believe that East German clinics faked the "deaths" of their children, who were actually stolen by the dictatorship and perhaps also given away.

Many are mothers who, shortly after giving birth, were told that their babies had died, but were prevented from seeing the body.

Though there is no written proof that hospital staff or state authorities abducted babies to give or sell to other couples, Frank Schumann, spokesman of Stolen Children of East Germany, believes there was a system in place that could have been connected to child trafficking, organ trade or even medical trials.

"They virtually set it out without written instructions, and crafted a system themselves," he told DW. "And the existing structures fully exploited the opportunities and possibilities afforded by a state secret police, for example, or a state security service."

Read more: Divorced East German women still waiting on equality, 30 years later

Inconclusive exhumations

The group has carried out five exhumations over the past five months, but so far, none have produced conclusive results. In one grave, no remains were found at all; in another, there were only animal bones.

Schumann urges families going down this route to be prepared for the different eventualities.

"It's important to think about the consequences of the results, how to deal with the outcome," he says. "Because if you've had doubts for 40 years and then suddenly there's a result on your doorstep, you have to be able to come to terms with it."

Even if there are no guaranteed answers, because the Ranisch family has drawn blanks at archives, which can legally scrap files after three decades, they now believe an exhumation and a DNA test are their best options.

"We want to have clarity," Ivonne says, acknowledging that even if the site does contain her brother's remains, they will still never know how he died.

Read more: Inmates of East Germany's juvenile homes speak out

Pieces from the past

Huddling together in their winter jackets, the family members peer into the grave. The air is heavy with suspense. After about 15 minutes of digging, the undertaker pulls out what looks like a femur, and parts of a skull.

They are too big to be from a child, he says, and probably belonged to whoever was buried there before. A little deeper down, there are splinters of what look like bones, but they turn out to be fragments of the white wood coffin that was committed to the ground all those years ago.

What comes up next is the sleeve of a small shirt, and another piece of clothing that Karin immediately recognizes.

It is the tights she provided for her son's burial. They're rotting at the seams, and contain pieces of bone. The undertakers also unearth what they believe to be part of a child's skull, but there is no sign of the femur and knee bone.

If the remains are not from Christoph, Ivonne says the family will have to go down a different search avenue, but that they would not have much to go on.

"They would have changed his birth date, they would have changed his name, so he's not Christoph Ranisch anymore," she says. "The only way he could be identified would be through scars from the scalding on his chest and arms."

A systematic operation?

Florian Steger, medical historian and Director of the Institute of the History, Philosophy and Ethics of Medicine at the University of Ulm in southern Germany is leading a research project that aims to shed light on cases in which parents believe their infants did not die in hospital, but were taken from them.

He has spent the past few months interviewing mothers, fathers and siblings, reviewing birth and death certificates, autopsy reports and Stasi documents, and is planning to release his results in mid-2019. So far, he says, he's found no evidence to suggest a systematic operation. But he doesn't rule out the kind of undocumented approach put forward by Frank Schumann — although it would have depended on a lot of people keeping quiet.

"And a lot of them also would have had to have been under so much pressure from the state that they were compelled to commit this offense," he told DW. "The state would have had to do a lot to make sure they stayed quiet."

Read more: Child abuse in the GDR — First taboo, then ignored

Publicity surrounding these cases has led to some developments. In September, the parliamentary group of Chancellor Angela Merkel's CDU/CSU bloc said it was looking into legislation to extend retention periods for archives at hospitals, adoption centers and birth and death registers.

It also wants to create a database where potentially affected parents or children can submit their DNA for comparison.

The waiting game

Back in the cemetery, the undertakers have dug as deep as makes sense. Their finds, which are laid out on a white sheet, include skull fragments and part of a jaw bone with teeth.

The remains will be sent to a forensic lab in Bonn, along with a DNA sample from Karin. After 40 years of wondering, a final result could be a few weeks away.

"I've never been at peace, always thinking he's alive, because we never had closure. If it's settled now with the DNA, and if he's in there, then it's ok, then he had his peace." 

But if the DNA test proves inconclusive, or it's not a match, Karin says they won't let up.

"Then the search will go on. I don't know if we'll find anything out, that will be very hard. We'll see what happens. We're definitely not going to give up."