NSA whistleblower Edward Snowden says he has more revelations about Washington's spying on German citizens, but Berlin is reluctant to invite him to testify because Germany has used the exact same surveillance methods as the US, Stern magazine reported.

The former NSA contractor – wanted by the US for disclosing its surveillance program – told the German magazine that he had been "personally involved with information stemming from Germany" and that the "constitutional rights of every citizen in Germany were infringed" during the process.



Snowden said he had used systems able to intercept large amounts of data, adding: "I'd be surprised if German lawmakers learnt nothing new if I laid out all the information."



The rights activist suggested that the only reason Merkel’s government does not want him to testify is because Germany's foreign intelligence agency, the BND, used the same methods of mass surveillance.



"The BND is with the Americans in bed," he told Stern.



So far it is unclear whether Snowden will be invited to Germany to provide new details for the investigation. Merkel’s government has rejected quizzing him in person, citing diplomatic reasons. The chancellor’s Christian Democratic Union party believes a personal invitation would put a strain on US-German relations. But despite the pressure from the government, the majority of German lawmakers on a committee investigating the spying decided earlier this month that they wanted to hear the leaker in person.



In response to the interview published in the German magazine on Tuesday, the chairman of the parliamentary committee, conservative lawmaker Patrick Sensburg, questioned Snowden’s competence in the matter.



“According to the information we have Edward Snowden was never especially involved with the mass spying of German citizens in Germany,” he said, as quoted by Reuters. "If he doesn't deliver proof in terms of original documents soon, he could lose all credibility with the committee."



Germany’s center-left Social Democrats (SPD), the second major political party after CDU, took a neutral stance, saying that it is open to questioning Snowden in Germany or Russia, while German opposition members involved in the investigation believe that Snowden is a key witness and should testify in person.



Since Snowden leaked sensitive US information last year, he has been charged with theft of government property, unauthorized communication of national defense information, and willful communication of classified intelligence to an unauthorized person.