The head of the UN"s nuclear watchdog has cancelled planned interviews with the BBC in protest at the corporation's decision not to air an emergency appeal for Gaza on behalf of the Disasters Emergency Committee.
In a statement to the Guardian, Mohamed ElBaradei, a Nobel peace prize winner, unleashed a stinging denunciation of the BBC, deepening the damage already caused by the controversy.
The statement, from his office at the International Atomic Energy Agency (IAEA), said the BBC decision not to air the aid appeal for victims of the conflict "violates the rules of basic human decency which are there to help vulnerable people, irrespective of who is right or wrong".
It said the IAEA director had cancelled interviews with BBC World Service television and radio, which had been scheduled to take place at the World Economic Forum in Davos on Saturday.
A BBC spokesman said: "We regret that Mr ElBaradei was not able to participate in an interview with the BBC while he is at Davos.
"Our audience around the world remains interested in what he has to say about a range of topics, and we hope he will accept an invitation at another time."
ElBaradei is due to leave his post as the IAEA director general in November.
He won acclaim for his scepticism over western claims that Saddam Hussein was attempting to develop nuclear weapons and his public opposition to the invasion of Iraq.
ElBaradei and the IAEA were awarded the Nobel peace prize in 2005.
Officials in ElBaradei's office said it was unclear how long his boycott of the BBC would last.
A spokeswoman said she expected him to review his position in light of how the corporation eventually resolved the row.
Both the BBC and Sky decided not to air the appeal by the DEC, an umbrella group of non-governmental humanitarian agencies, for aid for Gaza victims.
The appeal was broadcast by ITV, Channel 4, and Channel Five last night, and was watched by a combined audience of 4.5 million.
A voiceover at the beginning of the broadcast said: "This is not about the rights and wrongs of the conflict - these people simply need your help."
The BBC director general, Mark Thompson, said the appeal was not broadcast by the corporation because it would have damaged the impartiality of its coverage of the conflict.
Watch the Gaza aid appeal by the Disasters Emergency Committee rejected by the BBC and Sky