International pressure is growing on UK Home Secretary Jack Straw over his decision to stop the extradition to Spain of former Chilean dictator General Augusto Pinochet.

The Spanish judge spearheading attempts to bring General Pinochet to trial has demanded a second medical examination.

Judge Baltasar Garzon asked for fresh tests after those carried out by the British Government found the general unfit to be tried in Spain for human rights' violations.

Meanwhile, other countries are also maintaining pressure on the government.

The French Government has renewed its request for a French judge to question General Pinochet about the disappearance of five French citizens in Chile during his military regime.

The country's foreign minister, Hubert Vedrine, said the government continued to attach the greatest importance to the complaints of French and Franco-Chilean victims.

Belgium also said it would continue to press for the general's extradition on torture charges.

Speaking earlier in the week, Mr Straw said the tests had left him "minded" to halt extradition proceedings against General Pinochet on health grounds, meaning the former dictator would be allowed to go home to Chile.

But in a submission to the Spanish Government, to be sent on to the UK, Judge Garzon said a second set of tests should be carried out with the participation of Spanish National High Court doctors.

A spokesman for the judge, Joan Garces said: "Spanish justice needs to include in the Pinochet proceedings medical records on his mental incapacity so that a decision can be made whether or not to bring an end to the Spanish case."

He added that the petition to Mr Straw was based on Spanish and international law.

Straw defends position

While Judge Garzon's submission must reach London by Tuesday, it could be blocked by Spain's Foreign Ministry, which has reserved the right to refuse to send on the papers.

The judge's move came after Mr Straw defended his decision not to disclose the results of the tests on General Pinochet, despite agreeing to hear submissions from those demanding his extradition.

But Amnesty International and human rights groups have said they were already consulting lawyers over a possible judicial review of Mr Straw's decision not to release the medical results.

"Seeking representations from the parties without providing them with the medical report and opinion denies natural justice," said a spokesman.

General Pinochet's supporters say that since his arrest, he has suffered from a number of strokes and depression, further exacerbating diabetes, renal and heart problems.

But in a House of Commons statement on Wednesday, Mr Straw hinted it was a mental rather than physical incapacity which left the general unfit to stand trial.

He said the criteria he considered when making the decision included "whether Senator Pinochet would be in a position to follow the proceedings, whether he could give intelligible instructions to those representing him and whether he could give a coherent statement of his own case and recollection".