By Kim Sengupta  (The Independent, London)

3 March 2000

It was 5 October 1998 and General Augusto Pinochet had just taken tea at his old friend Baroness Thatcher's home in Belgravia, central London. As he was being driven away he spotted an old man begging by the roadside. Pointing, he said to his bodyguards: "Look, fat fish". It was a particularly cruel private joke. "Fat fish" was a term used by the Dina, the secret police created by Pinochet, for the political prisoners killed in one of his torture camps and thrown to the sea for the fish.

Pinochet was happy. The hospitality of Lady Thatcher – who called him "my general" – had, he believed, confirmed his standing in Britain. This was in stark contrast to most of western Europe, where he was unwelcome. Just a few days previously there had been an embarrassing snub from the French government, which had refused him permission to return to his father's ancestral roots. That refusal was to prove a ticking bomb for Pinochet.

In Britain, on the other hand, he had been a regular and welcome visitor during the Thatcher and Major years. It was a mutually beneficial relationship. One of the lucrative perks General Pinochet had given himself had been a key role in arms purchases by the Chilean military, and he had been a good customer for British firms.

His shopping, along with the obligatory trips to Harrods, Burberry's and Fortnum and Mason, was to take in the Royal Ordnance. His opponents claim he was hoping for a hefty commission for the purchase of three Type-22 frigates bound for the Chilean Navy. It was his second visit since Labour came to power and, as with the previous occasion, he had received a VIP welcome at Heathrow airport on 22 September.

The general was due to undergo minor back surgery and he was advised that he should combine his trip to Britain with a visit to the London Clinic in Harley Street to have this done.

It was there, 11 days after tea with the Thatchers, that Pinochet's past caught up with him in the most unexpected way. A midnight visit from Scotland Yard detectives led to his arrest, following an extradition request from the Spanish magistrate Baltasar Garzon. The general was to face charges of murder, torture and hostage-taking. Garzon had learned about his presence in London from French newspaper reports of his unsuccessful attempt to get into France.

The arrest led to uproar. In Britain it opened up old battle lines between right and left, with the latter gaining some unexpected advocates. Peter Mandelson declared it was "gut-wrenching" that "such a brutal dictator" should be claiming diplomatic immunity and Tony Blair was to describe the old dictator as "unspeakable". But these were isolated cries from New Labour's radical past. The official party line was that the issue was a purely legal and not a political matter. It was left to backbenchers like Jeremy Corbyn to carry on the campaign against Pinochet.

The general, in the meantime was being portrayed as a latter-day Dreyfus by his supporters. The common thread linking Pinochet's British supporters was often Lady Thatcher. She, and former chancellor Lord Lamont, were to become his most vocal advocates.

Abroad, the Pinochet supporters comprised an eclectic bunch including the Pope and the Dalai Lama. There was also strong lobbying from the Americans, especially former president George Bush and Henry Kissinger, apprehensive about prolonged public airing of the role the CIA had taken in Chile in overthrowing the government of Salvador Allende.

Within days of his arrest he was asked to leave the London Clinic and then the Grovelands Priory Hospital, before a £10,000-a-month home was rented for him by the Chilean government on the exclusive Wentworth estate.

The Pinochet camp was convinced that it would only be a short time before Jack Straw was forced to release him. Around £3m was raised in Chile, and huge sums were sent over and distributed in Britain to mount a propaganda campaign on the general's behalf. Hundreds of supporters were flown to Britain to show their "spontaneous loyalty". They picketed outside Belmarsh magistrates court, in south-east London, when he appeared there. The PR firm Bell Pottinger was reportedly given a £200,000 contract by the Pinochet Foundation to push his case.

The legal battles began with a victory for the general in the High Court when three judges, including the Lord Chief Justice, Lord Bingham, ruled that he had immunity from prosecution as a former head of state. The appeal to the House of Lords by the Crown Prosecution Service, on behalf of the Spanish government, was seen as mainly a paper exercise. Instead, the Law Lords voted by three to two that the former dictator, on his 83rd birthday, should face extradition.

The decision was greeted as a landmark in international human rights laws. The news of it brought spontaneous applause from MPs in parliaments across Europe.

But then came another twist in the tale with the revelation that Lord Hoffmann, who had voted against Pinochet, had links with Amnesty International, which had appeared in court to press for extradition. Despite the fact that Pinochet's own solicitors, Kingsley Napley, had donated money to Amnesty, the Lords decision was set aside.

In the fresh hearing that followed, the Lords upheld their previous decision by six to one, however they severely restricted the scope of the extradition action by ruling out many of the charges and inviting Mr Straw to reconsider. He did so, and allowed the extradition to continue. At that stage, the Home Secretary was the hero of the human rights groups and demonised by the Pinochistas. Times soon changed.

Pinochet lost round after round of his legal battles. A crucial loss, at Bow Street magistrates court, where stipendary magistrate Ronald Bartles ruled that additional charges put forward by Judge Garzon could be admitted, was followed by stories that the general's health had deteriorated badly.

The former dictator's path home was now secure. A further legal victory by Belgium, another state seeking extradition, and the human rights groups, this time against Mr Straw, could not prevent the Home Secretary using his "discretion" to free Pinochet.

The Pinochet affair ended with the impassioned recriminations with which it had begun. But the former dictator returns home a humiliated figure, whose brutality while in power has been held up to public opprobrium. As one human rights activist said yesterday: "We regret he did not face trial for his crimes. But what has happened in the last 16 months has put Pinochet where he belongs, in the dustbin of history."