The secret services watchdog CTIVD is concerned about the impact on privacy when the Dutch security services work together with foreign agencies.

A report by the watchdog outlining its position on alliances with foreign agencies was presented to MPs on Wednesday, a week after a narrow majority of voters rejected new laws giving the security services wider powers in a referendum.

The report says more has to be done to guarantee privacy when information is shared with foreign security services. Although there are advantages to working together, such alliances raise questions about protecting constitutional rights and the effectiveness of the supervision, the report states.

Potential problems arising from foreign agencies having access to information about Dutch nationals was one of the key themes in the referendum campaign.

The report, which was completed some time ago, was not published ahead of the referendum because time was needed to discuss the conclusions with foreign agencies, the home affairs ministry said.