Fearsome dog of Falklands war is revealed

Captured in the conflict with Argentina, Alfredo Astiz proved a headache for Britain

Alfredo Astiz, the last prisoner of war ever to be held in Britain, following the Falklands conflict, was considered so deadly by the British government that it wanted to get rid of him "as soon as possible". An Argentine naval commander, Astiz was captured by British military forces who retook the island of South Georgia in the southern Atlantic in April 1982.

The Argentine occupation of South Georgia in March 1982 precipitated the Falklands conflict between Britain and Argentina. Astiz led a group of marines posing as scrap metal merchants who landed on the island before raising the Argentine flag. British forces retook the island a month later and Astiz and his men surrendered.

But Astiz's capture caused a major headache for the British, according to Foreign Office files opened at the National Archives under the 30 years rule.

As soon as his identity became known, Swedish and French diplomats asked London to question him about his involvement in the kidnap of a 17-year-old Swedish girl and the murder of two French nuns in Argentina. Before the Falklands conflict, Astiz had been a member of a notorious special unit deeply involved in kidnapping, torturing and killing opponents of the ruling Argentine military junta.

Later dubbed the "Blond Angel of Death", Astiz infiltrated opposition groups, identified their members and arranged for their kidnap. Last year, Astiz was found guilty of crimes against humanity by an Argentinian court, which heard evidence that he and other members of the unit were complicit in the murders of up to 20,000 fellow citizens during Argentina's so-called "Dirty War" during the 1970s and early 1980s.

Astiz and his men were initially held prisoner on a Royal Navy ship at Ascension Island. He was kept prisoner after his men had been freed to return to Argentina. One memo from an MoD official, dated 18 May 1982, states: "My Secretary of State's [John Nott] main concern is that we have already steered very close to the wind in our treatment of Astiz – his custody on board ship is a breach of Article 22 of the Geneva Convention and there is, of course, the point that we have shown discrimination in our handling of him compared with the treatment given to his men.... Mr Nott feels that the only course of action is to get him off our hands as soon as possible."

In just a few days, he had assaulted a guard and later fashioned a "primitive dagger" from a bed spring, according to the documents.

After Astiz was flown to the Royal Military Police Barracks in Chichester, the British government became involved in a diplomatic row with Sweden and France, both of which requested that he be handed over for questioning about the kidnappings and murder.

According to Whitehall lawyers, Astiz could not be handed over to another country, and English courts did not have the power to try Astiz, as the crimes of which he was accused did not involve British nationals. The documents show that they were also concerned for the safety of British prisoners held by Argentina.

William Spencer, a specialist at the National Archives, said: "Of all the prisoners captured by the British, Astiz was the only one who was transported all the way back to the UK. Unaware of his history at the time of his capture, it soon became apparent that the British had one of the most dangerous individuals in the Argentine forces."