MEMBERS of Pablo Neruda’s family are contesting toxicology reports on the exhumed body of Chile’s most famous poet that appeared to reveal he was not assassinated, as many have believed since his death in 1973.

After seven months of forensic tests, it was announced on Nov 8 that no signs of poison had been found in the remains of Neruda — the man Gabriel Garcia Marquez called “the greatest poet of the 20th century in any language”. Yet some of Neruda’s family are not satisfied and have asked for the examination of the body to continue.

Neruda died at the age of 69 on Sept 23, 1973, just 12 days after Augusto Pinochet’s military coup. His body was exhumed from home at Isla Negra, on Chile’s Pacific coast, on April 8, 2013, following claims by the poet’s driver, Manuel Araya. He maintains that, although Neruda was suffering from prostate cancer, his illness was under control and his death was accelerated on the orders of the Pinochet junta by an injection in his stomach as he lay in his hospital bed in Santiago.

It is known that Neruda had been offered safe passage out of Chile to Mexico on Sept 22 by the Mexican ambassador, Gonzalo Martinez Corbala. Araya insists that the poet was murdered the following day to prevent him from fleeing into exile where, as a world-renowned member of the Chilean Communist party, he would have presented a powerful voice of opposition to the Pinochet regime.

For more than half of this year, 15 forensic scientists in Chile, US and Spain examined Neruda’s remains, seeking any indication of toxins. On Nov 8, Dr Patricio Bustos, director of the Chilean forensic service, announced: “No relevant chemical agents were found besides the pharmacological chemicals used at that time for prostate cancer. Neruda died of natural causes, due to his prostate cancer.”

Neruda’s family is divided. One of his nephews, Rodolfo Reyes, is unconvinced by the forensic findings. He cited a report released on Nov 6 by a Swiss laboratory on the remains of the Palestinian leader, Yasser Arafat, indicating results consistent with polonium poisoning. “We have to keep investigating,” said Reyes. In stark contrast, another of Neruda’s nephews, Bernardo Reyes, is certain that Neruda died of natural causes.

So, four decades after his death, 1971 Nobel prize winner Neruda remains at the centre of a continuing intrigue. Indeed, the story took a bizarre new twist in late July this year, when Attorney Eduardo Contreras, who represents Chile’s Communist party, requested further tests to confirm whether the remains being examined were actually those of Pablo Neruda at all.

Contreras pointed out that this was the third time Neruda’s body had been exhumed: he had previously been moved to the General Cemetery in Santiago in 1974, then for a second time in 1992 to be buried at Isla Negra. Judge Mario Carroza agreed to allow these tests, adding that, if necessary, the DNA of the remains would be compared with that of Neruda’s parents, who are buried in southern Chile.

Araya appears to be totally unpersuaded by the forensic report. In an interview, he declared: “After more than 400 tests on his remains, they were unable to say what Neruda died of. They need to do more investigations, and the judge is going to order these. We are sure he was murdered, because he was not close to death.”

For his part, Carroza told journalists that it was still impossible to state with certainty whether Neruda was murdered or not: “This will take more time.” One of the scientists involved in the tests on Neruda’s remains, Spain’s Francisco Etxeberria said: “We didn’t find any forensic evidence indicating that [Neruda’s] death was not a natural one.” Nevertheless, he conceded that analysis of bone, especially after four decades, was much more difficult than testing a recently deceased body.

Araya’s contention that Neruda was not in a critical condition at the time of his death is contradicted by some of the friends who visited him in a clinic in Santiago in the last days of his life. They told me they found him extremely ill.

Others, however, claimed that he was lucid, pointing out that he was continuing to dictate his memoirs to his secretary. Neruda’s widow always maintained that his cancer was under control. The official hospital medical records relating to Neruda’s death have also vanished, adding to the mystery.

On May 31 this year, Carroza issued an order for the police to track down a certain Dr Price — the man said to have been treating Neruda to the end. Although there is no record of a Dr Price in any of the hospital’s archives, the description of Price is reported to match that of Michael Townley, a CIA double agent who worked with the Chilean secret police under Pinochet.

Asked why it was so important to determine precisely how Neruda died, the Chilean writer Antonio Skarmeta said he still believed Neruda died of cancer. “Yet there is legitimate doubt. The whole affair is extremely sad, especially the removal of Neruda’s remains from his beloved home at Isla Negra. But Chile needs to know for certain what actually happened and [if he was murdered], the criminals have to be tracked down.”

The writer is the author of Pablo Neruda: A Passion for Life.—By arrangement with the Guardian