German news magazine Der Spiegel reported on Sunday that Israel and at least one other foreign intelligence agency regularly eavesdropped on US Secretary of State John Kerry's calls last year. The conversations in question are from when Kerry held almost daily negotiations for peace with various leaders in the Middle East - talks which collapsed earlier this year.

Spiegel said Israel used the information in its own negotiations because it knew what Kerry had been talking to the other sides about. It said its story, citing "several sources among secret services," could further strain ties between Israel and the United States.

"A large number of these conversations, which went via satellite, were listened to by at least two intelligence agencies, including the Israelis," the magazine wrote.

"It is probable that the Russians and Chinese were also listening in."

"The government in Jerusalem used this information in the negotiations on a diplomatic solution in the Middle East," Spiegel wrote.

The magazine said that while Kerry has a secure phone at his home in Georgetown, in Washington DC, he sometimes used an ordinary phone while traveling or when he needed to make a quick call. These vulnerable satellite connections enabled intelligence agencies to listen in, said Spiegel.

Kerry managed to bring Israeli Prime Minister Benjamin Netanyahu and Palestinian President Mahmoud Abbas back to the negotiating table in July 2013, as part of his push to revive Middle East diplomacy.

But those talks collapsed in April this year, when Israel announced plans to build 700 new settlements and refused to free a final group of Palestinian prisoners. Abbas in turn sought Palestinian membership in 15 UN conventions.

Kerry flew to Israel last week but has not been able to bring about a lasting truce to the current Israeli military offensive in Gaza, which has claimed more than 1,700 lives.

jr/av (Reuters, AFP)