A few months before his death in 2005, Simon Wiesenthal remembered something he had promised his wife, Cyla.

"Three to four years," he had told her -- that's how long he would hunt Nazi criminals from Vienna before the family could move to Israel.

The Wiesenthals never left the Austrian capital as Simon ended up devoting his entire life to bringing the Holocaust's perpetrators to justice.

"If you want to cure Malaria, you have to live with the mosquitoes," he said to friends who asked him why he wouldn't leave despite the hostility, death threats and even a bomb attack on his home. "A soldier belongs on the battlefield."

The documentary "I Have Never Forgotten You: The Life and Legacy of Simon Wiesenthal," which premiered at the Berlin International Film Festival, tries to shed light on why Wiesenthal didn't keep the promise to his wife.

"How could I simply restart my life where it had been interrupted and build houses?" Wiesenthal, an architect by trade, asked after emerging from the Nazi's Mauthausen death camp barely alive and weighing only 45 kilograms (99 pounds).

Labor of love

Using interviews with the man himself as well as conversations with family members and friends, the film's director, Richard Trank, recounts Wiesenthal's life from his birth in a small Polish village through the horrors of the Nazi era to his role as the world's most prominent prosecutor of war criminals.

Produced by Moriah Films, which is associated with the Simon Wiesenthal Center in Los Angeles, the documentary shows its subject in the best light possible and those behind it made no secret of their admiration for Wiesenthal.

"It was something from the heart," Trank, who has worked on several film productions for the center, said after the screening in Berlin.

Painting a full picture

Despite this, the film also contains scenes about moments of controversy in Wiesenthal's life.

"I wanted a full picture," Trank said. "We didn't want to skip over some of the more controversial parts of his life."

Those include allegations that Wiesenthal may have taken too much credit for hunting down Holocaust organizer Adolf Eichmann, who was hanged in Israel in 1962.

There is also discussion about accusations that Wiesenthal -- based on false information -- acted irresponsibly by saying that Nazi doctor Josef Mengele, who killed thousands for medical experiments at concentration camps, was still alive while he had already died years earlier. The documentary includes Wiesenthal's war crimes accusations against the leader of Austria's FPÖ party, Friedrich Peter, which led Peter's political ally, Austrian Chancellor Bruno Kreisky, to accuse Wiesenthal of employing mafia methods.

Contagious obsession

But these episodes in the movie pale in comparison with the praise by Wiesenthal's admirers, including Sir Ben Kingsley, who played Wiesenthal in the1989 film "Murderers Among Us: The Simon Wiesenthal Story."

"It was an obsession he had and when you were around him you became addicted," said Kingsley, who also attended the screening. "He was like a dad to me. He is still part of my cellular tissue. He taught me a great deal."

Education tool

Trank said the movie had already found a distributor in Germany and would be released in the US in late spring before going on to television and DVD.

"Most importantly, it will be used in schools," he said.

Wiesenthal Center officials meanwhile said they were planning to translate the movie into Farsi and find a way to broadcast it in Iran, where the country's president, Mahmoud Ahmadinejad, recently hosted a conference questioning that the Holocaust actually took place.

"We will find a way for people to see it if they want to find out the truth," said Rabbi Abraham Cooper, the center's associate dean.