Salvador Allende came under intense pressure from CIA-backed campaign during his brief presidency [GALLO/GETTY]

The remains of Salvador Allende, the former Chilean president, will be exhumed in hopes of finally determining whether he committed suicide or was executed by the military during a 1973 coup.

Chile remains locked in a decades-old controversy over Allende's death in his presidential palace on September 11, 1973, in the midst of the coup that brought general Augusto Pinochet to power.

The official version of events was that Allende killed himself with an assault rifle that was a gift from then-Cuban president Fidel Castro, as the presidential palace was under attack from the air and ground.

An inquiry was launched earlier this year to determine the cause of death.

His remains will be exhumed on Monday morning at 10:30GMT from a Santiago cemetery and analysed by a team of Chilean and international forensic experts.

Among those who will observe the exhumation and investigation is Luis Fondebrider, a world renowned forensic anthropologist who has helped identify the remains of hundreds of victims of political violence from across Latin America, Africa and Asia.

Neither the weapon nor bullets were recovered and Pinochet's military regime prevented Allende's family from seeing his corpse after the coup. There was no criminal investigation into his death.

A Chilean prosecutor announced the inquiry in January, as part of an investigation into human rights complaints against Pinochet's 1973-1990 military dictatorship.

Allende became Chile's first and only elected Marxist president in 1970. He was 65 years old when he died.

An autopsy conducted shortly after his death at the military hospital in Santiago determined the cause of death was suicide - a self-inflicted gunshot under his chin.

And Patricio Guijon, a doctor who was inside the presidential palace, also claimed Allende shot himself with an AK-47, which was a gift from the Cuban revolutionary Castro.

But Castro, other leaders and foreign journalists long questioned the official version of suicide, arguing that the leftist Latin American icon could have been executed by soldiers.

These doubts were reinforced in 2008 when medical examiner Luis Ravanal claimed, on the basis of the original autopsy, that Allende's injuries were inconsistent with a self-inflicted gunshot. He said there were two bullet wounds.

Allende's family still believes it was a suicide, but thinks it is necessary to clear up the circumstances that surrounded his death.

Allende had warned that he was ready to die before surrendering to the military. He had lasted just three years in office during intense pressure from a CIA-backed campaign to undermine his government.

Following the autopsy, his remains will be transferred to the Legal Medical Institute for examination.

Source: Al Jazeera and agencies