Iran's judicial authorities have again denied a request by President Mahmoud Ahmadinejad to visit Evin prison where his top media advisor is serving time, Iranian media reported on Wednesday, in another sign the president's power is on the wane.

Ahmadinejad's request was seen as linked to the detention of his press advisor Ali Akbar Javanfekr who was jailed for six months in September for publishing an article deemed offensive to public decency.

The judiciary turned down his first request to visit on Sunday, saying it was not in Iran's best interests for him to spend time on such a visit at a time when the country is facing an economic crisis. Ahmadinejad replied accusing the judiciary of unconstitutional conduct.

"Taking into account the recent letter and circumstances, on no account will a visit to Evin prison be allowed without coordination," Sadeq Larijani, the head of the judiciary, said on Wednesday, Iran's student news agency reported.

"The notion that the president has the right to supervise other powers (the judiciary) is completely false," he said.

Ahmadinejad's influence within Iran's factionalised power structure has weakened since a bitter feud erupted in public in 2011 over the supreme clerical leader's reinstatement of the intelligence minister whom Ahmadinejad had sacked.

The president is also facing growing criticism for exacerbating harsh Western sanctions over Iran's nuclear programme with misguided economic policies.

In the coming weeks, he may be summoned before hostile MPs for the second time this year to again explain his performance.