The first case concerns a serial rapist mostly in the area around Mol, Antwerp province, but also in Leuven, Geel, Dessel and Meerhout, between August 2003 and January of last year. The man, identified as Joan S, is suspected of 17 rapes and two sexual assaults, usually involving girls aged between 16 and 20.

In January last year police started a large-scale investigation that involved taking DNA samples from local men between the ages of 30 and 45 in Mol, Balen and Geel. The suspect, who has not been named, gave his sample last week, one of the last selected for testing. Investigators assume he committed suicide knowing he was about to be discovered. DNA traces were left by the rapist on 12 of the victims, the prosecutor’s office at Turnhout said. In the other cases, there were enough similarities to link them to the others.

Forensic labs are now calling for the extension of the DNA database to include all convicted criminals. At present, only those sentenced to five years or more can be made to give a sample. In the Mol rapist case, members of the public who were selected to give samples did so voluntarily, and their details will not be kept on file.

Belgium’s DNA database counts some 20,000 samples, with about 3,000 being added every year. By contrast, in the UK anyone who is arrested may be obliged to give a sample, adding up to a database of three million samples.

Meanwhile, one of the two men suspected of the brutal rape of a 17-year-old girl in Ghent last September also took his own life last week, after his accomplice threatened to go to the police. The man, identified as Jurgen D, dragged the girl into his studio apartment, tied her up with tape and held her for hours while the two men raped her repeatedly.

Later, the accomplice, Robin G, threatened to go to the police unless he received €10,000. He has now been arrested. The basis of the threat has not been explained. Police investigating the suicide discovered evidence including a letter about the blackmail. Up to that point, the investigation had foundered.