The kidnappers of an Italian journalist in Afghanistan have offered to free him in exchange for a Christian convert who fled the country, an aid agency says.
Torsello is a Muslim convert
Photojournalist Gabriele Torsello was seized last week while travelling on a bus in southern Afghanistan.
The kidnappers will free Mr Torsello, a Muslim convert, if Abdul Rahman returns from Italy where he was granted asylum earlier this year, the aid agency says.
Mr Rahman had escaped a possible death sentence for becoming a Christian.
He had been charged with rejecting Islam and released this March after being deemed mentally unfit to stand trial on a charge of apostasy.
'Not a spy'
Mr Torsello's kidnappers placed their demand in a phone call to the head of security at a hospital in southern Afghanistan run by Italian aid agency Emergency, said the Italian-based PeaceReporter website which is linked to the agency.
Christian convert Abdul Rahman took up asylum in Italy
The kidnappers demanded the exchange of the two men should take place before the end of the Muslim holy month of Ramadan which falls early next week, the website added.
The foreign ministry in Rome has not commented on the demands, but an Italian politician who helped obtain asylum for Abdul Rahman ruled out any exchange.
"It is not a demand that a decent human being would ever consider," the politician, Rocco Buttiglione, told the BBC.
"We are not ready to offer one human life for another human life... It is barbarian, inhuman, and it grinds against any accepted convention on human rights."
Media rights body Reporters Without Borders said it was "very concerned" about the fate of Mr Torsello.
"He is not a spy or a bargaining chip, but a courageous journalist," a statement said.
It is still unclear whether the kidnappers belong to any group.
Mr Torsello, himself a Muslim convert who is based in London, was reportedly kidnapped while travelling in a bus between the restive provinces of Helmand and Kandahar.
He phoned a local hospital to say he had been kidnapped on Thursday and did not know where he was, an Italian newspaper reported.
An Afghan news agency says it called his mobile phone and was answered by a man claiming to be from the Taleban.
Helmand and Kandahar have seen fierce fighting between Taleban militants and Nato-led foreign troops.
The Pajhwok news agency quoted Mr Torsello's travelling companion Gholam Mohammad as saying that he had been seized by five gunmen.
A Taleban representative who spoke to Reuters news agency distanced himself from the kidnapping, blaming it on criminals.
Gabriele Torsello says in his online CV that he is a "photojournalist specialising in war zones and hostile environments, mainly in Jammu and Kashmir and Islamic countries/areas".
Two German journalists were shot dead by unknown attackers in northern Afghanistan earlier this month.
Karen Fischer and Christian Struwe, two freelances working for Deutsche Welle, are believed to have been the first foreign reporters to be killed in the country since 2001.