The famously austere Mr Ahmadinejad has been criticised by his own allies after attending the lavish opening ceremony of the Asian games in Qatar, a sporting competition involving 13,000 athletes from 39 countries. The ceremony featured Indian and Egyptian dancers and female vocalists. Many were not wearing veils.

Women are forbidden to sing and dance before a male audience under Iran's Islamic legal code. Officials are expected to excuse themselves from such engagements when abroad but TV pictures showed Mr Ahmadinejad sitting with President Bashar Assad of Syria and Ismail Haniya, the Palestinian prime minister, during last Friday's ceremony in Doha.

Religious fundamentalists, usually Mr Ahmadinejad's keenest supporters, are asking why he attended a ceremony that violated his own government's strict interpretation of Shia Islam.

The Baztab website, considered close to Mohsen Rezaee, a former revolutionary guard commander with links to powerful sections of Iran's political hierarchy, said Mr Ahmadinejad's presence had offended Shias in Iran and elsewhere. "The failure of Ahmadinejad to object and his constant presence has damaged the image of Iran's Islamic revolution and its commitment to Islamic rules in contrast with the Arab countries in the Gulf," it said.

The president's aides insist he was not present during the singing and dancing. His press secretary, Ali Akbar Javanfekr, claimed Mr Ahmadinejad had left for Doha airport before the performance.

However, Baztab posted footage which purported to show Mr Ahmadinejad in his seat after the show. Jalal Yahyazadeh, a rightwing MP, said: "We have heard from some sources that Ahmadinejad was in the stadium at the time. Those who created the conditions for his presence should be investigated as quickly as possible."