A man who says he is an Iranian nuclear scientist claims to have escaped after being abducted by US agents.
In a video shown on Iranian state TV, he says he has escaped in the US state of Virginia and is now on the run.
Mr Amiri disappeared a year ago while undertaking the Hajj in Saudi Arabia.
Two videos purportedly showing him surfaced three weeks ago. One said he had been kidnapped, the other that he was living freely in Arizona.
The US has strenuously denied abducting him, but ABC News reported in March that Mr Amiri had defected and was helping the CIA compile intelligence on Iran’s controversial nuclear weapons programme.
The state department has refused to say whether he is in the US.
In the new video, broadcast on Tuesday, a man claiming to be the missing scientist says: “I, Shahram Amiri, am a national of the Islamic Republic of Iran and a few minutes ago I succeeded in escaping US security agents in Virginia.
“Presently, I am producing this video in a safe place. I could be re-arrested at any time.”