German Ministers Urge Swift Answers to U.S. Double-Agent Reports

German ministers on Sunday called for a swift response from the U.S. to allegations of spying by a suspected double agent, which have raised fears of fresh tensions between the two allies.

"I expect now for everyone to assist in the speedy clarification of the accusations, and quick and clear statements, also by the U.S.," Interior Minister Thomas de Maiziere told Bild newspaper in comments released ahead of Monday's edition.

Hot on the heels of revelations last year that the NSA allegedly tapped Chancellor Angela Merkel's mobile, the latest reports of U.S. spying by a German foreign intelligence service employee have sparked anger among some politicians.

The U.S. ambassador was asked to attend a meeting late on Friday at the foreign ministry, following initial media reports that a 31-year-old man arrested last week had been feeding information to a US agency for two years.

Foreign Minister Frank-Walter Steinmeier said in a tweet on Sunday during a visit to Mongolia that the expectation had been expressed to the U.S. envoy that his country help "in clarification as quickly as possible"

"If reports are correct, we are not talking here about small potatoes," Steinmeier added.

Germany's federal prosecutor general confirmed last week that a man had been arrested Wednesday on suspicion of acting for a foreign intelligence service, but did not specify which one.

"All signs indicate that he was acting for the Americans," the Frankfurter Allgemeine Sonntagszeitung (FAS) newspaper quoted an unnamed senior official at Germany's foreign intelligence service, the BND, as saying.

The FAS and the weekly Bild am Sonntag newspaper, which cited information from security officials, said the man had worked for the CIA and had handed over more than 200 documents in return for 25,000 euros ($34,000).

Both newspapers also said the suspect had passed on two documents about a parliamentary panel established earlier this year to investigate NSA surveillance after revelations by fugitive former intelligence contractor Edward Snowden.

On the Berlin stop of a tour to promote her book "Hard Choices", former U.S. secretary of state Hillary Clinton said she only knew what she'd read in the press but stressed the need to get to the bottom of the claims, calling it a "serious issue."

"I believe strongly in the necessity of the German-U.S. partnership and friendship, even though I know there have been strains in recent months," she said.

Germans were outraged by revelations last year that the NSA had allegedly eavesdropped on Merkel's conversations, as well as wider U.S. surveillance of Internet and phone communications.

Last month federal prosecutors said they had opened a criminal investigation into alleged illegal U.S. snooping on Merkel's mobile phone.

The revelations strained ties between Washington and Germany, a key European ally, which both countries' leaders have been at pains to repair.

But President Joachim Gauck said in an interview with ZDF to be aired later Sunday that if the latest suspicions are confirmed, "then it probably really has to be said, now it's enough," warning that a friendship and close bond were at stake.

Reports say that German authorities were alerted to the suspect when he sent an email with attached files at the end of May to the Russian consulate offering to supply information.

After they tracked him down, he claimed, when questioned by authorities, that he'd been handing over information to the Americans for two years, Bild am Sonntag said.

He was employed in a BND department dealing with protection for German soldiers deployed overseas, among other things, FAS said.