Shane Bauer and Josh Fattal (Reuters photo)
Shane Bauer, aged 28 and Josh Fattal, 29, were arrested with Sarah Shourd, 32, on the unmarked border between Iran and Iraq on July 31, 2009.
Iran has accused the three of "spying and illegally entering the country."
They have pleaded not guilty to spying charges, saying they were hiking in Iraq's northern province of Kurdistan when they innocently strayed into Iran across the unmarked border.
Washington has vehemently denied Tehran's charges and has pressed for their release.
Shourd is being tried in absentia after she returned to the United States following her release on humanitarian and medical grounds in September 2010, for which bail of about 500,000 dollars was paid.
"Since the hearing date coincides with the two year anniversary of their arrest, and it is the beginning of the holy month of Ramadan, I am hopeful that this case has a happy ending," their lawyer Masoud Shafii told AFP on Wednesday referring to the Muslim fasting month when compassion, the spirit of caring and sharing is advocated.
"I believe that they are innocent; the espionage charges have no relevance. Even if the court does not accept my defence, the two years they've spent behind bars is punishment enough," he added referring to the illegal entry charge.
The trial has been hit by a number of delays since November 6, 2010, when it was postponed to February 6, 2011 over what was termed "an error in the judicial proceedings."
Another hearing scheduled for May 11 this year was cancelled after Fattal and Bauer were not brought before the court, Shafii said at the time.
Shourd, who did not attend the February 6 hearing, told AFP in Washington that she will not return to Iran to join the other two in the dock.
She said she had sent Iran's revolutionary court a five-page evaluation by a clinical forensic psychologist, who concluded she was at high risk of psychological problems if she returned to face espionage charges.
Shafii said he has met Bauer and Fattal only twice, the last time on February 6, 2011 when they appeared in court for the first hearing.
"I still have not met them (for) the lawyer-client meeting that I have requested. They told me that they will inform me and I am still pursuing it," he said.
Iran in late May implicitly rejected a US State Department request to grant better access to the two by allowing Swiss diplomats to see them. Switzerland represents US interests in the absence of Washington having diplomatic relations with Iran.
Swiss embassy officials also insist they have been unable to meet the detained hikers since October 2010. They were also banned from attending the February hearing.
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