Ofcom has launched a formal investigation into Iran's Press TV following a complaint by Newsweek journalist, Maziar Bahari, who spent 118 days in a Tehran jail after being arrested while covering protests over the disputed presidential election last June.

Bahari, who was sentenced to 13 years and six months, complained that Press TV, which is controlled by the Iranian government with a bureau in west London, had screened an excerpt from an interview with him while he was in jail.

He accused Press TV of obtaining the interview while he was under extreme pressure in a prison interrogation room.

Bahari noted that while he was compelled to read from a prepared script, his interrogator prompted questions to the interviewer from behind a curtain.

He argued that the Press TV broadcast breached Ofcom's code and was a mockery of the notion of informed consent.

In an interview with Channel 4 News, which will air on Thursday night, Bahari is likely to express his woes against Press TV, which launched in Britain promising to be independent and deliver unbiased views and reports.