The arrest of a seven-member suspected terrorist cell last month was partly down to an undercover police officer who befriended the group over a period of several months, the NRC and RTL reported on Thursday.

In addition, the undercover policeman, who first approached the gang’s alleged leader by email, supplied weapons to the gang, which had been made safe, the papers said.

The seven men from Arhem and Weert were remanded in custody earlier this week while the investigation continues.

Police said at the time of the arrests they had foiled a major terrorist attack but it remains unclear what event the gang was planning to disrupt.

The department began an investigation into the 34-year-old man they suspect to have led the cell in April, following a tip-off from the AIVD security service. The AIVD said the man, an Iraqi national, had been planning an attack at a major event in the Netherlands with the aim of creating as many victims as possible.

‘The plan may have involved jackets packed with explosives and Kalashnikovs at an event and a car bomb elsewhere. The investigation into the exact target is still ongoing,’ the public prosecution department said.