( CNN ) -- Pablo Neruda wooed readers with his romantic poetry , but the latest lines in his story could be ripped from a murder mystery . The Chilean poet 's 1973 death certificate says prostate cancer killed him . But his former chauffeur has another theory involving an unknown assassin , a lethal injection and the South American country 's notorious military coup . On Monday , authorities started putting that theory to the test , exhuming the poet 's remains as part of a high-profile investigation that could take months to complete . Manuel Araya , the chauffeur , said he 's received threats for making the controversial claim , which has riled some of Neruda 's supporters . That wo n't stop him from speaking his mind , Araya told CNN Chile . `` I am not afraid of anyone , '' he said . Chauffeur : 'They silenced him ' Neruda died on September 23 , 1973 , just 12 days after a right-wing military coup ousted socialist President Salvador Allende and brought Gen. Augusto Pinochet to power . The poet , a Communist Party member , had criticized the coup and Pinochet . Less than two weeks later , he was dead . He had been planning to go into exile the next day -- and the timing of his death was no coincidence , according to Araya . Neruda was a well known political and public figure , having served as a lawmaker and diplomat in addition to his literary career , which earned him a Nobel Prize in 1971 . `` I believe that Pablo Neruda was murdered , because Pablo Neruda was a very relevant figure in history , as much in this country as in the world , '' Araya told CNN Chile . `` He was going to go into exile on September 24 and they silenced him before then . '' Thousands of people disappeared or died during Pinochet 's rule , and many have accused his government of using death squads to wipe out political opponents . Araya alleges that Neruda was poisoned in a clinic where he was undergoing treatment . That claim and several other alleged discrepancies surrounding the poet 's death drew the attention of Chile 's Communist Party , which called for Neruda to be exhumed in 2011 . Evidence suggests that a third party was involved in Neruda 's death , said Communist Party attorney Eduardo Contreras . Chilean Judge Mario Carroza ordered the exhumation in February . Nephew : 'This is a circus ' But not everyone shares the Communist Party 's concerns . After the exhumation request , the head of the Pablo Neruda Foundation -- founded by the poet 's widow to promote and preserve his legacy -- said he did n't want authorities to dig up Neruda 's remains . `` We are against an exhumation of his cadaver because it would seem to us a true act of desecration , '' Juan Agustin Figueroa told Chile 's Radio Bio-Bio in 2011 . The organization has since adopted a more welcoming tone . `` In this year that marks four decades since the death of Pablo Neruda , we hope also that the investigation of Judge Carroza will help clarify the doubts that might exist regarding the poet 's death , '' the foundation said in a statement last week . Others are n't convinced . `` This is a circus that I do not want to be part of , '' Bernardo Reyes , Neruda 's nephew and biographer , said last week . Reyes said party officials never contacted him to discuss their desire to have Neruda 's remains exhumed , and he told CNN Chile that he remains suspicious of their motives . As debate surges , Reyes said he plans to update a biography of Neruda and publish photographs taken of the poet after his death , which show Neruda 's physical state and the clothes he was wearing in his coffin . `` It seems that when someone wants to find the truth but ignores all the sides of the story , that is notable , '' he said . Expert : Time 'erases evidence ' The investigation into Neruda 's death follows another high-profile exhumation . As part of a massive probe of 726 reported human rights violations during Pinochet 's rule , Chilean authorities exhumed Allende 's body in 2011 . Official accounts ruled the leftist leader 's death a suicide , saying that he shot himself -- with a gun that was reportedly a gift from Fidel Castro -- as Pinochet 's troops closed in on the presidential palace . In July 2011 , Chile 's Legal Medical Service confirmed that suicide was the cause of Allende 's death . For decades , Neruda has been buried alongside his wife , Matilde Urrutia , in Isla Negra , a coastal area in central Chile . Excavation crews began work there on Sunday and completed the exhumation on Monday , CNN Chile reported . Determining what really happened will be a difficult task , since so much time has passed since the poet 's death , one pathologist told CNN Chile . `` Time is a destructive factor , '' said Dr. Luis Ravanal , an investigator for the office of Chile 's government ombudsman . `` It is an element that erases evidence . '' Tissues will have decomposed , he said , and even if some sort of poison were used , there may no longer be any traces remaining . `` Science has enormous limitations in this case , '' he said .
Investigators exhume poet Pablo Neruda 's remains . His death certificate says he died of prostate cancer . His former chauffeur alleges he was killed by an injection . The claim has riled some of Neruda 's supporters .