The policeman arrested for leaking confidential files to criminal gangs last month passed on information about dozens of cases, the public prosecution service has told the NRC.

Mark M, 28, had been a police officer for several years when he was picked up on charges relating to leaking information in October. He had not been screened by the security services before his appointment.

Oost-Brabant prosecutor Nicole Zandzee told the NRC M had been actively collating information shortly before his arrest and had alerts on 23 different files. This meant he was informed if any changes were made in these cases.

‘But we don’t know how many alerts he had operating in the years before his arrest,’ Zandzee said. The police are hoping to find out more by analysing IT equipment including flashdrives containing police information which were found in his house and the home of his parents, she said.

As part of the investigation, the police have made a formal request to Ukraine for help, Zandzee told the paper, without giving further details. Mark M had a Ukrainian wife and made several trips to Kiev.

Zandzee did say M had no access to information about the downing of flight MH17 over eastern Ukraine and was not authorised to read it.