Prosecutors in the western German city of Cologne on Tuesday laid out the case against a man charged with almost 100 counts of child sexual abuse.

The man was said to have documented the abuse of babies, children, and teenagers, sharing videos and images of "unimaginable brutality."

What do we know so far?

According to the indictment, the 45-year-old is accused of sexually abusing children in 99 cases between 2005 and 2019, and of 124 offenses in total.

The man allegedly offered himself as a babysitter on the internet to find his victims, the Cologne Regional Court heard.

Investigators said they had uncovered vast amounts of incriminating data last year at the married man's home, in the small town of Wermelskirchen, some 30 kilometers northeast of Cologne. The arrest and raid took place in December last year.

They said at the time that they had never previously "encountered such a level of inhuman brutality and callous indifference to the suffering of young children.''

According to the court, the prosecution alleges that the defendant himself abused 13 victims, the majority of whom were boys. The victims were between eleven months and 13 years old. The accused is alleged to have harmed seven other children by aiding or abetting other perpetrators.

The prosecutors are seeking a sentence of 15 years imprisonment followed by preventative detention if the man, whose name wasn't released, is convicted.

The arrest led to a large number of further preliminary proceedings against other individuals. According to the public prosecutor's office, there are now more than 130 suspects.

Convictions in darknet case

In a separate case on Tuesday, a court in Frankfurt convicted four men for their involvement in the "Boystown" online platform which was used to spread images of child sexual abuse.

A 49-year-old man and a 42-year-old man were sentenced to 12 and 10 years in prison, respectively.

The court also sentenced a 60-year-old German man, who was arrested while sitting at his computer in Paraguay, to eight years in prison for his role in operating the darknet site.

Court officials said a 66-year-old man from Hamburg, who was considered a particularly active user,  was handed a seven-year sentence.

The Boystown site, with more than 400,000 members before it was taken down last year, was a major international platform for child sexual abuse material. Authorities say they are still working to identify and prosecute other users of the site.