Britain's highest court, the House of Lords, is about to begin a hearing to decide whether the former Chilean military ruler, Augusto Pinochet, can be extradited to Spain.

Five Law Lords will review an earlier court judgement that General Pinochet -- as a former head of state -- enjoys immunity from a Spanish judge's moves to try him over alleged atrocities involving Spanish citizens.

French prosecutors have asked for the General's arrest in a separate move for extradition, and legal action is proceeding in six other European countries.

The Spanish judge who initiated the original arrest has now formally asked the Spanish government to pursue extradition.

The former Chilean leader himself remains in a London hospital on bail.