Tehran, Dec 13, IRNA -- Iran's former judiciary chief Ayatollah Mohammad Yazdi here Friday called for treason charge indictments in the case of three pollsters who are being tried for allegedly passing top secret information to foreign countries.

"Isn't the passing of some classified documents of the system and false information to aliens betrayal and spying and how the world deals with spies," he told thousands of worshipers during weekly Friday prayers.

The case involves former student leader in the takeover of US embassy in Tehran, Abbas Abdi, as well as Hossein Qazian and Alireza Alavitabar -- all related to the Ayandeh research institute -- which published results of a survey, claiming that most Iranians favored dialogue with the US.

The fourth defendant in the case, Behrouz Geranpayeh, who is the head of the National Institute for Research and Opinion Polls, faces similar charges which have yet to be brought against him.

Qazian, Abdi and Geranpayeh are held in detention, but Alavitabar has not been arrested yet.

The defendants are accused of carrying out the research on the order of the Washington-based Gallup Organization as well as tampering with the results of the survey to portray it pro-American.

On Tuesday, the judge in the case, Saeed Mortazavi, accused Qazian of having secret contacts with elements linked to foreign intelligence services as well as propagating against the Islamic Republic.

The defendant rejected the charges, but admitted that he had made a mistake by agreeing to carry out the survey without being aware of the nature of the foreign organizations which had ordered the polling.

"Tampering with (the results of) a survey and documents constitutes betrayal since it instigates the public opinion for no reason," Yazdi said as he lashed out at those who claim the case was politically-motivated.

"The results published, which also prompted the reaction of some officials, were false as confessed in court sessions. But, despite this confession, it is still claimed that the case is political," the cleric said.

Ayatollah Yazdi urged the court to hold the trials in public in the face of some calls to hold them in camera.

"Our society should know why an institute like Ayandeh as well as another institute which has been mentioned, had access to top secret documents," he said.

"The people must know why the strictly confidential documents were in the hands of these people and that who really these people are, what they are doing and what their objectives are," the cleric added. cleric added.