The threat will overshadow a visit to London next week by Mr Kissinger, who will find himself hounded by an alliance of human rights campaigners and anti-capitalist demonstrators over his alleged connivance at General Pinochet's 1973 coup in Chile, as well as his part in the Vietnam war and America's secret bombing of Cambodia.

Mr Kissinger's planned speech to the Institute of Directors at the Royal Albert Hall on 24 April will be met by a mass protest – and preceded by 10 days of "Kissinger-bashing", beginning with a "Get Kissinger" press conference launched by Labour MP, Jeremy Corbyn, at the Houses of Parliament.

On 4 July last year Juan Guzmán, the Chilean judge, submitted some 30 questions to Mr Kissinger about his relationship with Gen Pinochet; the questionnaire was passed on by the US State Department, but he has not so far chosen to reply, and is not expected to do so. Nor is Washington likely to hand over to an international criminal tribunal a man who served as secretary of state to two presidents.

Any application for his extradition, however, would increase the embarrassment and pressure on Mr Kissinger, who last year quit France in a hurry rather than submit to a summons to appear before A judge Roger Le Loire, who was looking into the disappearance of five French citizens in Chile during the Pinochet years.

Mr Guzmán told The Independent on Sunday he would be pressing for Mr Kissinger's replies this month and if they did not come, extradition proceedings would follow. Such action would mirror the move by the Spanish judge, Baltasar Garzón, which led to the arrest of Gen Pinochet in London in September 1998. "I have been in touch with the US embassy here in Santiago, and they say they have no idea why replies have not been sent to my questions," said Mr Guzmán.

Guy Taylor, of the anti-capitalist movement Globalise Resistance, said there would be a "direct action blockade" when Mr Kissinger appeared at the Albert Hall. "We are calling on the Home Secretary not to allow him into the country," he said. "He presided over one of the most brutal eras of US foreign policy in history."

Mr Kissinger is still threatened by a $4.9m civil action from Joyce Horman for the death of her husband, Charles Horman, during Pinochet's 1973 coup, which formed the basis of the film Missing. He is also being sued in Washington by members of the family of the former Chilean army commander, General René Schneider. Schneider was assassinated in Chile in 1970 in what was seen as a plot, aided by the CIA, to prevent the election of the Socialist President Salvador Allende.