COPENHAGEN, Denmark — Sweden’s defense minister wants Denmark to explain why that country’s foreign secret service allegedly helped the United States spy on European leaders, including German Chancellor Angela Merkel, more than seven years ago.

“We want the cards on the table,’ said Defense Minister Peter Hulqvist who added it was “unacceptable to eavesdrop on allies.”

On Monday, Danish lawmaker Karsten Hoenge of the left-leaning Socialist People’s Party that is supporting Denmark’s Social Democratic government said he would quiz the Scandinavian country’s defense and justice ministers in parliament about the case.

“The government must explain how come Denmark has been acting as a willing tool for a U.S. intelligence service, and what it will mean for cooperation with Denmark’s neighboring countries,” he said.

The Danish broadcaster DR said the Danish Defense Intelligence Service, known in Denmark by its acronym FE, conducted in 2014 an internal investigation on whether the National Security Agency had used the cooperation with the Danes to spy against Denmark and neigboring countries.

The probe concluded that NSA had eavesdropped on political leaders and officials in Germany, France, Sweden and Norway.

According to DR on Sunday, the alleged set-up between the United States and Denmark was codenamed “Operation Dunhammer.” It allegedly allowed the NSA to obtain data by using the telephone numbers of politicians as search parameters.

DR said its report was based on interviews with nine unnamed sources, all of whom were said to have had access to classified information held by the FE. The military agency allegedly helped the NSA from 2012 to 2014.

Reports in 2013 that the NSA listened in on German government phones, including Merkel’s, prompted a diplomatic spat between Berlin and Washington that soured otherwise good relations with Barack Obama’s administration.

Merkel declared that “spying among friends” was unacceptable and said later that she stood by that comment. Still, there were also reports that Germany’s own BND intelligence agency may have helped the U.S. spy on European companies and officials.

In a written comment to DR, Danish Defense Minister Trine Bramsen said the government can not discuss intelligence matters.

She added the present government has “the same point of view ” as the former Social Democratic government led by Helle Thorning-Schmidt who was in power during that period: “the systematic wiretapping of close allies is unacceptable.”