DHAKA: The German authorities have summoned the US ambassador in Berlin after a man was arrested on suspicion of spying.

The US diplomat "was asked to help in the swift clarification" of the case, the foreign ministry said.

German officials confirmed the arrest but released no other details.

US-German ties were strained after allegations last year that the US National Security Agency bugged Chancellor Angela Merkel's phone as part of a huge surveillance programme, reports BBC.

The scale of the agency's global spy programme was revealed in documents leaked by a former intelligence contractor, Edward Snowden.

The revelations also raised feeling in Germany against American surveillance.

The BBC's Steve Evans in Berlin says the new allegation of American spying on an ally may make it harder for the US to get German help in its efforts to oppose Russian activity in Ukraine, and also to control Iranian nuclear ambition.

BDST: 1251 HRS, JUL 05, 2014