Iran insisted on Tuesday that nuclear scientist Shahram Amiri had been "kidnapped" by US agents, effectively dismissing reports he had defected to the United States.

ABC news in the United States reported last week that Amiri, an Iranian nuclear physicist in his early 30s who disappeared in June 2009 after arriving in Saudi Arabia on a pilgrimage, had defected and was working with the CIA.

"The US links with Mr Amiri only confirms our statement that they had a role in his abduction," foreign ministry spokesman Ramin Mehmanparast told reporters in reaction to the ABC report.

"Our services said he was abducted with US intelligence cooperation in Saudi Arabia, where he was on pilgrimage," he added.

The ABC report said that US intelligence agents described the defection as "an intelligence coup" in US efforts to undermine Iran's controversial nuclear programme.

Amiri's disappearance "was part of a long-planned CIA operation to get him to defect," ABC reported, citing unnamed people briefed on the operation by US intelligence officials.

Mehmanparast said the ABC report was also "ambiguous" in its attributions to Amiri and his work and this was "not acceptable" to Tehran.

The United States has led international efforts to thwart Iran's controversial nuclear work, which it suspects is aimed at developing atomic weapons.

Tehran insists its nuclear programme is peaceful and designed to meet domestic energy needs.