V�ctor Jara's music was popular throughout South America

Mr Jara was allegedly tortured and killed shortly after the military coup in September 1973 in a sports stadium, in the capital, Santiago.

Prosecutors hope to determine who was in charge of the stadium at the time.

The judge also ordered a number of former army generals to provide testimony concerning the case.

'He kept singing'

The judge's decision came as General Pinochet faces an investigation into allegations that he hid millions of dollars in secret bank accounts while in power.

The Chilean Supreme Court is also expected to rule on an appeal by his lawyers following a court decision to strip him of his immunity from prosecution in connection with Operation Condor - a drive against opponents of South American military regimes.

Mr Jara was one of the founding fathers of Chile's New Song movement and a supporter of President Salvador Allende, who was overthrown in the coup.

Mr Jara, who was 38 when he was tortured and killed, was reportedly held with other people who the military considered "dangerous".

Other prisoners were later quoted as saying that he did not stop singing even when guards burnt and broke his hands.