MOSCOW(Sputnik) — According to De Telegraaf, the investigation is related to the affair surrounding Interior Minister Ronald Plasterk and the 1.8 million telephone details shared with the US National Security Agency (NSA) in early 2014.
In October, the leak revealed that Plasterk had in fact confidentially informed the country's lower house of parliament about the agreement with the NSA that he publicly denied in 2014. This information was reportedly leaked from the so-called secret committee, discussions in which are strictly classified.
Halbe Zijlstra, leader of the ruling VVD party, made a formal police complaint about the leak, the media said.
According to the newspaper, the investigation has not yet gathered enough evidence to proceed with the complaint. Senior public prosecution department officials are now deciding on further steps, the media said.
A number of lawmakers have been questioned and their phone numbers were checked against the call history of the reporter who made the revelation, according to the media.
Some parliament members are reportedly concerned that their phones in the parliamentary complex are being tapped by the security services.
Dutch Interior Minister Ronald Plasterk denied in 2014 that the information on the 1.8 million phone calls and text messages had been sent to US secret services, after the revelations were first published in German Spiegel magazine in 2013. However, later Plasterk said the Dutch intelligence had been responsible for monitoring the phone calls, and that the information had been shared with the US authorities.