The head of a German parliamentary inquiry into foreign spying fears he may have been spied on himself, it has emerged.
The case could have repercussions for relations between the UK and Germany.
The government reportedly threatened recently to end intelligence cooperation with Germany over concerns about the inquiry.
Patrick Sensburg, the chairman of a Bundestag committee charged with investigating foreign spying on German soil, believes his mobile phone has been hacked, according to a report in Welt* newspaper.
The inquiry was set up last year after it emerged that the US National Security Agency (NSA) had listened in to Angela Merkel’s mobile phone calls.
Mr Sensburg and other high-profile political figures were issued with encrypted mobile phones that were supposed to be unhackable.
Mr Sensburg’s phone was sent to the Federal Office for Information Security (BSI), Germany’s IT security service, to be examined.
The phone was sent in a lead-lined sealed container. But when it arrived with it had clearly been opened and tampered with, according to reports.
It is not clear who may have interfered with the package. It was sent by the German courier company DHL. The BSI is now examining the phone.
If Mr Sensburg has been targeted by a foreign intelligence agency it could have implications for intelligence-sharing between the UK and Germany.
The government declined to confirm or deny reports last month that it had threatened to end cooperation with Germany’s intelligence agencies if members of the inquiry were given access to classified information on joint operations.
*S??ddeutsche Zeitung *newspaper reported this week that the German government was seeking a compromise under which only Mr Sensburg would be given access to the classified information in question, as chairman of the committee, and would report back to other members.
If he has himself been targeted in spying, it could end hopes for such a compromise.
The British warning came in a letter to Angela Merkel’s office from Paddy McGuinness, a Deputy Natiional Security Advisor, according to *S??ddeutsche Zeitung.* The German government is taking British concerns seriously, the newspaper reported. There have been a number of leaks from the inquiry, and Mrs Merkel’s office threatened its members with criminal charges after secret documents were leaked last October.
But under German law, the inquiry can challenge any government attempt to block it from seeing classified information in court, and at least two members have indicated they would go to the courts.
When reports of the British threat first emerged, a Whitehall source said the UK was “working closely with the German government to engage with the parliamentary inquiry”.
A Cabinet Office spokesman added at the time: “It is longstanding policy that we do not comment on intelligence matters”.
“It is longstanding policy that we do not comment on intelligence matters,” a government spokesman said on Monday. “We continue to work closely with the German government to engage with the German parliamentary inquiry.”