BBC Persian television is continuing to broadcast into Iran despite attempts to jam the station's signal.

The persistent interference began soon after BBC Persian began extended coverage of the death of leading reformist cleric Grand Ayatollah Hoseyn Ali Montazeri.

This includes the first airing of an exclusive interview with the grand ayatollah which was filmed before his death. The senior cleric, who had not been seen on Iranian television screens for 20 years, was one of Shia Islam's most respected figures and a leading critic of President Mahmoud Ahmadinejad.

The jamming began on Sunday 20 December and affected the Hotbird 6 satellite which carries the BBC's international television and radio services in various languages as well as services from other broadcasters.

BBC Persian television is also carried on other satellite networks including Telstar and Eutelsat W2M.

The BBC are looking at ways to increase the options for its Farsi-speaking audiences in Iran, Afghanistan and Tajikistan, which may include broadcasting on other satellites.

In June this year, BBC Persian television suffered similar deliberate attempts to interfere with its signal when airing extended coverage of the Iranian elections. At that time, the satellite operator traced the interference and confirmed it was coming from inside Iran.

BBC World Service Director, Peter Horrocks, said: "The fact that someone would go to these lengths to jam BBC Persian television's signal is indicative of the impact we make in Iran. The Iranian people want to know the truth about what is happening in their country, and they know they will get impartial and independent news from the BBC. We'll do everything we can to give them that news."