The BBC has claimed its Persian television service is again being jammed from within Iran following rolling coverage of the political turmoil currently engulfing Egypt.
The corporation said heavy electronic jamming of satellites it uses in the Middle East to broadcast the BBC Persian TV signal to Iran started last night.
Technicians working for the BBC traced the interference and confirmed that it is coming from Iran - as it did when protests against the re-election of Mahmoud Ahmadinejad began in Tehran in June, 2009.
Director of BBC Global News Peter Horrocks last night called for an immediate stop to the satellite jamming.
He said: 'The events in Egypt are being viewed by the entire world and it is wrong that our significant Iranian audience is being denied impartial news and information from BBC Persian TV.
'This is a regional story that Persian TV have been covering thoroughly and it is clear from our audience feedback that Iranian people want to know what is happening in Egypt.
'The BBC will not stop covering Egypt and it will continue to broadcast to the Iranian people."
The corporation said Persian TV had been working closely with its Arabic TV service to broadcast rolling news coverage from Egypt and it believes the impact of this coverage prompted this latest attempt to block its broadcast signal.
Today is also the anniversary of the Iranian Revolution and this, coupled with opposition leader Karubi being placed under house arrest yesterday morning, meant protests have been called over the next couple of days in Iran.
During the disputed Iranian elections in 2009, satellite transmissions of Persian TV came under sustained attack from within Iran forcing the BBC to extend is broadcast hours and increase the number of satellites used to transmit the service.
The BBC's Persian TV and Arabic TV are two services to have escaped the worst of wholesale cuts at BBC Worldwide and the World Service, which is to cut five other language services and around 650 jobs as it seeks to save £46m a year.