U.S. intelligence agencies have warned Germany that the flow of intelligence to Berlin could be cut following the arrest of August Hanning, a former president of Germany's Federal Intelligence Service (BND), on suspicion of espionage, according to the German public broadcaster's Tagesschau news program.
The Süddeutsche Zeitung reported that the U.S. notice reached the BND a few days after Hanning's arrest and that Washington was reviewing its past cooperation with the agency.
Former spy chief in custody

Hanning, 80, who led the BND from 1998 to 2005 and later served as a state secretary at the Interior Ministry, was arrested by the Federal Criminal Police Office on Oct. 6 and remains in pretrial detention. Federal prosecutors accuse him of intelligence agent activity, treasonous espionage, scouting state secrets and attempted treason.
Investigators say his former office manager, identified only as Manfred D. under German privacy rules, agreed in 2010 to regularly pass him BND intelligence in exchange for payment, roughly 2,000 documents in all. Hanning allegedly used the information in his consulting work. German media have reported that the material may have reached China. Hanning denies the allegations.
If confirmed, the case would be Germany's most serious espionage scandal since World War II.
Berlin: 'Trusting working relationship'
German security sources told the dpa news agency that there were currently no restrictions on cooperation between the BND and U.S. agencies, though some working meetings had been postponed and later rescheduled. The BND declined to comment, saying it does not discuss international cooperation.
Foreign Minister Johann Wadephul, speaking in Atlanta on the sidelines of the G20 foreign ministers' meeting, said he could not imagine intelligence cooperation being restricted. "We have a very successful and trusting working relationship between our intelligence services," he said.