Four men have been sentenced in Belgium for taking part in a vast child pornography case that has already identified a total of 90 suspects and 110 victims worldwide, it was learned on Wednesday.
At a court hearing on Tuesday, the men received sentences ranging from 5 to 16 years in prison. A psychological appraisal was ordered for a fifth man.
According to the Belgian federal police, this is "one of the biggest cases of sexual abuse of minors ever known".
The investigation began in 2015 when a policeman became suspicious of the actions of a Belgian man in his thirties who was taking pictures of children in bathing suits on a beach in the town of Blankenberge.
Nine million images
A search of the suspect's computer uncovered "about 15 terabytes (TB) of files" containing child pornography - some nine million images.
The trial involved three Belgians, including the first suspect arrested on the beach, one Dutch and one British man.
Over five years, with the help of the European police agency Europol, the investigations uncovered a network of photo and video exchanges touching 44 countries.
"These were images of abuse of babies as young as a few months old and teenagers between 12 and 13 years of age. The child victims were mainly male," the Belgian police said in a statement.
A total of 110 victims were identified, as well as 90 suspects, Europol noted in a separate statement.
Many suspects are still wanted, but some have already been tried and convicted in several countries. In Australia a man was sentenced to 15 years in prison.
According to the Belgian police, "international cooperation is continuing with a view to identifying as many victims and suspects as possible".