Privacy watchdog Autoriteit Persoonsgegevens (AP) has fined 10 local councils in the Netherlands a total of €250,000 for unlawfully monitoring Muslim communities without their knowledge.

Local council officials included information about people’s political preferences and religion in the files, which is a breach of the privacy rules, the AP said. Some of the data was also shared with the anti-terrorism unit NCTV and the social affairs ministry.

The local councils involved were Delft, Ede, Eindhoven, Haarlemmermeer, Hilversum, Huizen, Gooise Meren, Tilburg, Veenendaal and Zoetermeer.

The scandal came to light following an article in the NRC in 2021.

“People have been investigated without their knowledge. Reports contain sensitive information about their religion and other personal information about them and their families,” AP chair Aleid Wolfsen said.

“The councils had no grounds whatsoever for having that information. The privacy of these people has been breached in the worst possible way, and that has affected their trust in the local authorities.”

The government and the NCTV had urged local authorities to do more to combat radicalisation following the terrorist attacks in Europe in 2015 and 2016 and to prevent youngsters joining up with IS.

The 10 councils which have been fined have admitted they went too far in their investigations – acting as “private police forces” – and including details about family relationships and tension between mosque officials, the AP said. Detailed personal files were compiled on some people.

The AP said that the fine was based on the seriousness of the breaches, including mitigating factors such as the relatively short period in which they took place and the political pressures at the time.

“What the local councils did damaged their relationship with the people involved,” Wolfsen said. “They recognise they were wrong and are trying to build bridges. In hindsight, they were insufficiently aware of their role and responsibility. They admit they broke the law and are prepared to pay up.”