Does AIVD have authority to investigate? Or can AIVD participate in an investigation?

That depends on the question. If the question refers to investigations pursuant to our legal duties (intelligence and security, and security screenings), then the answer is: yes. If the question refers to a police investigation, then the answer is: no.

The legal basis for our duties is Article 8 of the Security and Intelligence Services Act 2017. The AIVD may also participate in a joint investigation, together with one or more services from other countries, provided this remains within the AIVD's stipulated duties.

The AIVD does not particpiate in police investigations. Article 8 does not provide any basis for such a possibility.