BERLIN - The US National Security Agency tapped phone calls involving German Chancellor Angela Merkel and her closest advisers for years and spied on the staff of her predecessors, according to WikiLeaks.
A report released by the group suggested NSA spying on Merkel and her staff had gone on far longer and more widely than previously realised. WikiLeaks said the NSA targeted for long-term surveillance 125 phone numbers of top German officials.
The release risks renewing tensions between Germany and the United States a month after they sought to put a row over spying behind them, with US President Barack Obama declaring in Bavaria that the two nations were "inseparable allies".
A German government spokesman said on Thursday Berlin was looking into the latest report and reiterated that such events strained German and American intelligence cooperation.
The United States repeated its position that it did not undertake foreign intelligence unless there was "a specific and validated national security purpose."
State Department Spokesman John Kirby said in an email, "This applies to ordinary citizens and world leaders alike. Germany is a close friend and partner on a range of issues, and we look forward to continuing and deepening this important relationship."
Friends and associates of former NSA contractor Edward Snowden have denied he is the source of the latest WikiLeaks revelations, suggesting that they likely came from a different and still unidentified leaker deep inside US intelligence.
However, some US officials familiar with the latest leaks said they were unaware of other leakers and believe that one way or another the material newly published by WikiLeaks did somehow originate with Snowden, even if he did not give it directly to Assange.
WikiLeaks published what it said were three NSA intercepts of Merkel's conversations, and data it said listed telephone numbers for the chancellor, her aides, her office and even her fax machine.
The intercepts detailed communications from Merkel in 2009 on the international financial crisis, with the crown prince of the United Arab Emirates in 2009 on Iran, and with advisers in 2011 on the euro zone crisis.
The targeted phone numbers included those for the cellphones of senior officials at the chancellery and included that of Ronald Pofalla, Merkel's former chief of staff, WikiLeaks said.
Spying is a sensitive issue in Germany. The Snowden revelations have caused outrage in Germany when they first surfaced.
The spying row has also been stirred by allegations that Merkel's staff gave the German BND foreign intelligence agency a green light to help the NSA spy on European firms and officials.