Germany has brought a halt to a long-term internet surveillance operation carried out for the US NSA intelligence service amid a growing scandal over the extent of its intelligence co-operation with Washington, according to Financial Times.

German media reported on Thursday that the German foreign intelligence service this week suddenly stopped supplying the US with internet-based data under the terms of a longstanding co-operation pact.

The move could revive strains in security relations between the US and Germany that emerged two years ago when whistleblower Edward Snowden disclosed widespread global snooping by the NSA, including the tapping of German chancellor Angela Merkel’s mobile phone.