WARSAW — Poland's Deputy Prime Minister and Defense Minister Tomasz Siemoniak and his Dutch counterpart Jeanine Hennis-Plasschaert have been targeted by unknown perpetrators who bugged a restaurant in Warsaw where the two officials met for talks April 1, reported local broadcaster TVN 24.

The bug "was found by the Military Counter-Intelligence Service as part of a routine, thorough search. And the important part of the talks took place earlier at the MoD," Siemoniak tweeted.

A bugging device was found at the restaurant prior to Siemoniak's meeting with Hennis-Plasschaert who was on an official visit to Warsaw. The Polish prosecutor's office has launched an investigation to determine who installed the device in the VIP room.

The Dutch minister's visit was focused on NATO policy, the alliance's Readiness Action Plan (RAP) and plans related to establishing a Very High Readiness Joint Task Force (VJTF), the Polish Defense Ministry said in a statement.

Sources close to the investigation told the broadcaster that the device was "professional, miniaturized and enabled to record in a high quality".