Iran has cancelled Saturday's planned release of US hiker Sarah Shourd, accused of spying and illegally entering the Islamic republic, because of unresolved legal issues, officials said.
"Because the judicial process has not been fulfilled in the mentioned American defendant's case, (her) release has been ruled out," Tehran prosecutor Abbas Jafari Dolatabadi said in a statement carried by the ILNA new agency.
"The judiciary does not validate the published news and naturally any decision about the defendants will depend on carrying out the judicial process," he said of reports about her expected release.
State news agency IRNA reported President Mahmoud Ahmadinejad's office as saying Shourd's release had been postponed.
"The freedom of the American citizen which was to happen in a ceremony has been postponed as Saturday was a holiday," IRNA quoted an unnamed presidency source as saying.
|Detained US hiker Sarah Shourd (L) sits with her mother Nora during their first meeting since her arrest, in the Iranian capital Tehran in May 2010|
An earlier version of IRNA's report quoted presidency office spokesman Mohammad Hassan Salehimaram as saying that the "details of her release will be announced later."
Releasing Shourd could have eased tensions between Washington and Tehran, which have heightened in recent months over Iran's controversial nuclear programme.
Several officials had earlier indicated that Shourd, one of three American hikers held for more than a year, would be freed on Saturday.
Shourd, 31, was arrested along with Shane Bauer and Josh Fattal on July 31, 2009 after straying across the border from neighbouring Iraq. They have been accused of spying and illegal entry.
The three insist they entered Iran by mistake after getting lost during a trek in Iraqi Kurdistan.
Reports of Shourd's expected release first emerged late on Thursday in a culture ministry text message to news networks inviting them to report on the event on Saturday.
But on Friday foreign ministry spokesman Ramin Mehmanparast cast doubt on the expected release, telling English-language Press TV that "discussions are still ongoing regarding the details and the date of her release."
Shourd's release would have coincided with the end of Ramadan and the anniversary of the September 11, 2001 attacks in the United States.
Her mother Nora told AFP last month that Shourd was being held in solitary confinement despite suffering from a pre-cancerous cervical condition, a lump in her breast and depression.
The mothers of the trio had voiced hope that news of one of them being released signalled an end to their battle for freedom.
"We have seen the news reports and are urgently seeking further information," Cindy Hickey, Nora Shourd and Laura Fattal said in a joint statement.
In May, Iran had allowed the mothers to visit, and they later reported that Shourd and Bauer had become engaged behind bars.
On Thursday, the United States said it was checking the veracity of reports of Shourd's pending release with Switzerland, which has represented American interests in Iran since the aftermath of the 1979 Islamic revolution.
"These are three innocent children, innocent kids who committed no crime, all three of whom should be released and released immediately by the Iranian government," White House spokesman Robert Gibbs said.
US President Barack Obama and Secretary of State Hillary Clinton, Nobel Prize winners and international rights groups have repeatedly urged Iran to release them.
Last month, Iranian Intelligence Minister Heydar Moslehi said an investigation on the US detainees was nearing completion.
In April 2009, US-Iranian journalist Roxana Saberi was freed after being held on espionage charges, but US-Iranian scholar Kian Tajbakhsh, who was arrested in the unrest that followed Ahmadinejad's re-election in June 2009, remains in custody.
Another American, Robert Levinson, a former Federal Bureau of Investigation agent, went missing more than three years ago from Iran's Kish island. Tehran says it has no information about him.
In May, Iran released French academic Clotilde Reiss who was detained nearly a year earlier during the post-election protests.