A former police officer has gone on trial accused of systematically leaking information to criminals for four years.

Mark M. is alleged to have run a network of underworld clients while training in the police force and passing on files from the police data system. An investigation found he had made 30,000 inquiries about 23 cases.

The 30-year-old from Weert is accused of running a criminal enterprise with two of his clients and an intermediary from Eindhoven.

After joining the force as a trainee M. had wide access to police records. His activities came to light when officers found leaked documents in the computer of a garage owner who was being investigated for suspected money laundering, which bore M’s digital signature.

M., whose trial at the district court in Den Bosch began on Monday, claims he has been wrongly accused and is the victim of ‘character assassination’ by former chief of police Gerard Bouman and justice minister Ard van der Steur.

Bouman labelled M. ‘one of the most rotten apples in ages’, while Van der Steur said he ‘deserved the hardest punishment’ for his alleged offences. M.’s lawyers said he had been publicly judged before he had been found guilty, compromising his chances of a fair trial.