BBC Legal Affairs Correspondent Joshua Rozenberg: New hearing will take place in New Year

Five Law Lords have unanimously set aside last month's ruling that General Pinochet must stay in the UK to face extradition proceedings.

The general's lawyers argued at the appeal that the original decision was unfair because one of the Lords involved, Lord Hoffmann, had links with Amnesty International.

Announcing the new ruling, Lord Browne-Wilkinson said: "I am satisfied that the earlier decision of this House cannot stand and must be set aside.

Lord Browne-Wilkinson announces the decision

"It is impossible in the time available to prepare and give full reasons for that view - on the other hand it is essential that the parties should know where they stand as soon as possible."

General Pinochet: Won latest appeal but faces more court tests

General Pinochet's lawyers had argued Lord Hoffmann's position - coupled with his wife's job with the human rights group - gave rise to "a real danger of bias".

The appeal was heard by a different panel of senior Law Lords - the other four verbally agreed with the position set out by Lord Browne-Wilkinson.

Chilean President Eduardo Frei said he was pleased with the new ruling.

The new hearing

The new hearing on the original immunity claim may take place next month and could take even longer than the original six-day process.

In addition to Amnesty, the Chilean Government could also seek to make representations, as well as Spain and other countries interested in extraditing the general.

Joshua Rozenberg discusses the unprecedented Lords' vote

A spokeswoman for Amnesty International said the organisation remained hopeful that General Pinochet would be extradited.

"We will be going back to the Lords. We will be hoping that the decision once again goes in our favour," she said.

Lord Hoffmann's links to Amnesty International sparked an appeal

Lord Hoffmann, a director and chairman of Amnesty International Charity Ltd, cast the deciding vote in the original Lords ruling, which was passed by a 3-2 majority.

The judgement cleared the way for Mr Straw's decision to authorise the lengthy extradition process, as Spanish authorities seek to try General Pinochet for crimes including mass murder.

At the appeal, Clare Montgomery, QC, for General Pinochet, said that Lord Hoffmann was under an obligation to declare his links to Amnesty, so that the legal team could decide whether they wanted to object to him hearing the case.

But Alun Jones, QC, for the Spanish Government, argued there would have been chaos if Lord Hoffmann had declared his links to Amnesty.