Legal moves against the former Chilean dictator have also begun in France and Sweden.

In Paris, the families of three alleged victims of the general's military regime have asked the French authorities to request his extradition.

Joshua Rozenberg: "General Pinochet is accused of killing at least 4000 people"

And in Stockholm, three Chilean exiles have reported General Pinochet to the Swedish police, accusing him of involvement in the kidnapping and murder of family members.

The latest moves against the former military leader came as his legal team tried to secure his release in London.

General Pinochet: Blamed for 4,000 deaths

The 82-year-old general was arrested 10 days ago at the request of a Spanish judge who wants him extradited to Spain on charges of genocide and torture.

The Swiss extradition warrant is expected to be passed on to Scotland Yard in the next 24 hours.

It follows a request by prosecutors in Geneva investigating the torture and disappearance of a Swiss-Chilean national, Alexis Jaccard, in 1977.

Son of Allende's secretary 'murdered'

Legal Affairs Correspondent Joshua Rozenburg reports from the High Court

A memorandum calling for General Pinochet's extradition has also been lodged with the French Justice Ministry.

The document says his state police killed Enrique Andres Maria Ropert Contreras, the son of former president Salvador Allende's personal secretary.

The 20-year-old's body was found on the banks of the Mapocho river in September 1973.

The memorandum also blames the general for the disappearance of two other French nationals.

Rene Chanfreau, 23, was arrested by "armed men dressed as civilians", but never returned from the Colonia Dignidad, the Chilean political prison.

Etienne Pesle, 49, was detained by Chilean airforce officers in 1973 and never resurfaced.

Pinochet 'sent assassins to Spain'

The general's supporters call for his return home

The charges on the Spanish extradition warrant relate to alleged abuses between 1973 to 1990.

A second warrant issued on 22 October accuses him of torture, hostage taking and conspiracy to murder.

Alun Jones, QC, for the Crown Prosecution Service, told the High Court the former dictator was responsible for the deaths of "at least 4,000 people".

He also accused him of sending agents to Spain to "seek out and kill" political opponents.

But General Pinochet's legal team say his arrest is unlawful because he has immunity from arrest for actions committed while he was head of state.

His lawyer, Clive Nicholls QC, said any attempt to deny the general immunity would open up the prospect of the Queen being extradited from America to Argentina for the murder of Argentinian nationals killed in the Falklands.

Home Affairs Correspondent Jane Peel reports from the court

Mr Nicholls argued that releasing him did not raise the spectre "of a Hitler going unpunished".

He said the correct channel was an international court set up by the UN.

Meanwhile, a Chilean aircraft has landed at RAF Brize Norton, sparking speculation that the UK government intends to release General Pinochet "on humanitarian grounds". The allegation has been denied.

Hospital treatment

General Pinochet is being held at a London clinic where he was arrested on 16 October while recovering from major surgery.

But it was not the first time the general had sought treatment in Britain. Two years ago he had routine tests for a respiratory complaint at an Edinburgh hospital, according to the Herald newspaper.

He registered under his first two names, Augusto Ugarte, at the Western General Hospital in October 1996, the paper reported.