"With co-operation from the United States, Israeli covert operations have focused both on eliminating key human assets involved in the nuclear programme and in sabotaging the Iranian nuclear supply chain," she said.

"As US-Israeli relations are bound to come under strain over the Obama administration's outreach to Iran, and as the political atmosphere grows in complexity, an intensification of Israeli covert activity against Iran is likely to result."

Mossad was rumoured to be behind the death of Ardeshire Hassanpour, a top nuclear scientist at Iran's Isfahan uranium plant, who died in mysterious circumstances from reported "gas poisoning" in 2007.