Here are the transcripts of two videos allegedly featuring Iranian scientist Shahram Amiri, who disappeared last year while on a pilgrimage in Saudi Arabia.
In the first, broadcast by Iranian television, a man purporting to be the scientist says he was kidnapped by the US and is now living in Arizona, in what the Iranian government says is evidence he is being held in the US against his will.
In the second, posted hours later on YouTube, a similar-looking man claiming to be the scientist says he is happy in the US.
VIDEO BROADCAST ON IRANIAN TELEVISION
"I, Shahram Amiri, expert and researcher of Malek-e-Ashtar Industrial University, am currently in the American city of Tucson in the state of Arizona.
I was kidnapped last year (2009) in the holy city of Medina on 3 June in a joint operation by the terror and abduction units of the American CIA and Saudi Arabia's Istikhbarat [intelligence agency].
They took me to a house located somewhere that I didn't know. They gave me an anaesthetic injection. When I became conscious I was in a big [voice interrupted] towards America.
During the eight months that I was kept in America, I was subject to the most severe tortures and psychological pressures by the American intelligence investigation groups.
And the main aim behind these investigation teams and the pressure imposed on me was to make me take part in an interview conducted by an American media source and claim that I was an important figure in Iran's nuclear programme and I had sought asylum in America at my own will.
And (to say) while seeking asylum I took some very important documents and a laptop with classified information on Iran's military nuclear programme in it to America from my country.
The main aim from this was to impose political pressure on the Islamic Republic of Iran and in fact condemning (Iran) and proving lies that America has been constantly saying against the Islamic Republic of Iran.
I demand the organisations active in human rights issues in Iran and other countries to follow up my case seriously because I have unrightfully been abducted in a third country and have been brought to the US and I demand them to apply all their efforts to help me get freed and return to my dear country, Iran."
VIDEO POSTED ON YOUTUBE
"I, Shahram Amiri, a citizen of the Islamic Republic of Iran, am in America and intend to continue my education here. I am free here and I assure everyone that I am safe.
My purpose in today's conversation is to put an end to all the rumours and accusations that have been levelled at me over the past year. I am Iranian and I have not taken any steps against my homeland.
My wish is to see Iran and its people rising to the peaks of progress and success.
I do not hold any political views and have no interest in the political subjects and discussions of any state and country. I am not involved in weapons research and have no experience and knowledge in this field.
I know that the government of the Islamic Republic of Iran will take care of and protect my family. I want them to know that I have never left them and have always loved them.
I am asking everyone to stop presenting information that distorts the reality about me."