Germany’s Chancellor Angela Merkel said allegations that a member of its foreign-intelligence agency sold documents to the U.S. would be a clear contradiction of trusting cooperation.

If the reports are correct it would be a “serious case,” Merkel said in her first public comments on the matter at a press briefing with Chinese Premier Li Keqiang in Beijing Monday.

“If the allegations are true, it would be for me a clear contradiction as to what I consider to be trusting cooperation between agencies and partners,” she said.

The case, first reported by two German newspapers on July 4, risks adding to a U.S.-German rift over surveillance by the U.S. National Security Agency after documents leaked by former contractor Edward Snowden suggested the agency hacked Merkel’s mobile phone and spied on Germans. 

The office of Germany’s federal prosecutor said on July 3 that a 31-year-old German was arrested the day before on suspicion of spying for a foreign power that prosecutors declined to identify.

The man, a support technician for Germany’s BND foreign intelligence agency, met U.S. agents at least three times in Austria from 2012 to 2014 and gave them hundreds of secret documents for which he was paid 25,000 euros ($34,000), Bild reported. The documents were seized on a thumb drive and a laptop at the suspect’s home, the newspaper said July 4.

Merkel is on three-day visit to China and is due to speak at Tsinghua University in Beijing Tuesday.

The two sides signed several agreements Monday including a memorandum of understanding between Air China Ltd. and Deutsche Lufthansa AG, a deal for a new car plant in China for FAW Volkswagen Automobile Co., as well as a helicopter order with Airbus Group NV.

China also agreed to grant Germany an 80 billion yuan ($12.9 billion) quota under its RQFII program, which allows foreign entities to invest Chinese yuan in the domestic capital markets.

In separate remarks on industrial espionage, Merkel said Germany opposes it regardless of where it comes from. “We have a duty as the state to protect our economy,” she said. “We are for the protection of intellectual property.”

President Obama’s administration has said Chinese spy agencies are involved in a far-reaching industrial espionage campaign targeting biotechnology, telecommunications, clean energy and nanotechnology industries.

Li said Monday that the Chinese government “resolutely opposes” hacking attacks as well as the use of the Internet to steal commercial secrets or intellectual property. (Bloomberg)