Chilean poet Pablo Neruda did not die of prostate cancer, forensic experts have said.
The Nobel Laureate was said to have died of cancer in 1973, less than two weeks after a military coup led by General Augusto Pinochet.
But his former driver Manuel Araya maintains he actually died after being poisoned by the secret service.
New tests on Neruda's remains have now confirmed he did not die of cancer, but have yet to reveal the actual cause.
The mystery of Pablo Neruda's death
Dr Aurelio Luna told a press conference the experts were "100% convinced" that the death certificate "does not reflect the reality of the death".
The poet was suffering from prostate cancer, but it was not life-threatening - leading the 16 international experts to conclude a third party could have possibly been involved.
They will now carry out tests on a toxin found in his remains, which were exhumed on a judge's orders in 2013. It could be up to a year before the results are known.
Neruda was a supporter and personal friend of Chile's deposed socialist President, Salvador Allende.
The poet died on 23 September 1973, 12 days after the military coup and three days after he had been offered asylum in Mexico.
According to Mr Araya, the day he died he called to say he had been injected in the stomach while he was asleep, and to come to the hospital quickly.
Neruda died that evening, and Mr Araya says he has no doubt what killed him.
"Until the day I die I will not alter my story," Mr Araya told the BBC in 2013.
"Neruda was murdered. They didn't want Neruda to leave the country so they killed him."