The former dictator Gen Augusto Pinochet was freed because of a secret accord between Britain and Chile, according to a new book quoted yesterday by the Observer newspaper.
The claim is made in a book entitled Augusto Pinochet: 503 days trapped in London, by Chilean TV reporter Monica Perez and Felipe Gertdtzen, a son-in-law of former Chilean president Eduardo Frei.
They say the plan to free Gen Pinochet was established following a telephone conversation in mid-1999 between Mr Frei and British Prime Minister Mr Tony Blair, and that top Spanish officials were also involved.
Gen Pinochet was detained on October 16th, 1998 in London by officials acting on a warrant issued by Spanish judge Mr Baltasar Garzon, who sought to try him for crimes against humanity. He was held in Britain until March 2nd, 2000 while the courts debated whether he should be extradited.
British Home Secretary Mr Jack Straw eventually decided to let Gen Pinochet return home after two medical examinations declared he was too frail to stand trial.
But attempts to solve the judicial conundrum had included talks in Rio de Janeiro, New Zealand and New York between British Foreign Secretary Mr Robin Cook and his then Chilean counterpart, Mr Juan Gabriel Valdes, the report said.
Mr Blair, under pressure from Mr Frei to get the former dictator released back to Chile on humanitarian grounds - he had undergone back surgery in Britain - allegedly suggested establishing a "back channel" between the two capitals.
Mr Frei's press attache, Mr Cristian Tolosa, and Mr Jonathan Powell, an assistant to Mr Blair, were reportedly charged with secret contacts, and Mr Tolosa made six visits to London in the second half of 1999, the newspaper said.
Mr Blair's office declined to comment on the story at the weekend.
Mr Valdes also reportedly met then Spanish foreign minister Mr Abel Matutes at the Rio summit, leading to a plan under which Madrid officials refused to pass Mr Garzon's instructions on to British judicial officials.
"The freeing of Pinochet was a political decision taken by the British government," the newspaper quoted leading Chilean human rights lawyer Mr Hernan Montealegre as saying on Saturday. He added that the medical report which Mr Straw used to justify the release would not have held up in court.
Gen Pinochet failed to attend a court-ordered medical examination in Santiago yesterday.