The Tehran trial of three American hikers charged with spying was postponed on Wednesday because the two still in custody were not brought from prison, their lawyer and other sources said. A closed-door second session of the revolutionary court had been scheduled for Wednesday after the trial began on February 6 and lasted just a few hours. \"They did not bring Shane (Bauer) and Josh (Fattal) to the court (from prison) and I was not told why,\" the trio\'s lawyer Masoud Shafii told AFP. \"I waited in the court for two hours. The minutes of what happened were signed. The session will be postponed. I was not told about the (date) of the next session and I still was not able to see them,\" he added. \"It is certainly the fault of the judiciary since the prisons are under the judiciary,\" Shafii said. Bauer and Fattal, both aged 28, were arrested along with Sarah Shourd, 32, on the border between Iran and Iraq on July 31, 2009. They insist they lost their way while on a hiking trip. Shourd is being tried in absentia after she returned to the United States when she was freed on humanitarian and medical grounds in September, paying bail of around 500,000 dollars. Spokesman for the Iranian judiciary, Gholam Hossei Mohseni Ejeie, told Tehran-based Al-Alam Arabic language television, \"The session will not be held today. It has postponed to another time.\" He did not elaborate. The trial has been hit by a number of delays. It was first scheduled for November 2010 but then postponed to February 6 due to what was termed \"an error in the judicial proceedings.\" Shafii had earlier said he hoped Wednesday\'s hearing would be the last and that a verdict would follow soon. Ahead of Wednesday\'s planned session, the families of Fattal and Bauer issued a statement repeating that the two men were innocent and criticised the Iranian legal process. \"For more than 21 months, Shane and Josh have been locked up, isolated from their families and the world and denied any semblance of due process,\" they said in a joint statement. \"We call on the authorities to take this opportunity to end the mistreatment of two young men who have done no wrong to Iran and mean more to us than anything.\" The detention of the three has added to the animosity between arch-foes Tehran and Washington, which have deteriorated over Iran\'s controversial nuclear drive and outspoken remarks by hardline President Mahmoud Ahmadinejad. Iran has accused the three hikers of \"spying and illegally entering the country.\" The trio have pleaded not guilty to the spying charges and maintain they innocently strayed into Iran across the unmarked border with Iraq. Washington too has vehemently denied Tehran\'s charges and has pressed for their freedom. Shourd, who also failed to attend the February 6 hearing, told AFP in Washington last week that she will not return to join the other two in the dock. 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. Swiss embassy officials in Tehran have met the detained hikers five times in the 21 months of their detention, including when the mothers of the three visited them in Iran last May. The Swiss embassy represents US interests in Tehran since Iran and the United States have not had diplomatic relations for more than three decades. A Swiss official on Wednesday expressed frustration at the legal proceedings. \"We asked to attend the trial, and that has been denied. We have not been able to meet them in seven months. And today we were not told about the postponement of the trial,\" by the Iranian judiciary, the official said.