Santiago, Chile (CNN) -- Chile's Communist Party said it wants authorities to exhume poet Pablo Neruda's body as part of an investigation into his 1973 death.
"There is no other way to resolve this terrible doubt," lawyer Eduardo Contreras told Chile's Radio Bio-Bio in an interview quoted in a statement on the party's website.
The Nobel Prize-winning poet's death certificate says he died of prostate cancer, but Neruda's former chauffeur alleges that he was killed by an injection in the clinic where he was undergoing treatment, the Communist Party said.
Neruda died on September 23, 1973, just 12 days after a right-wing military coup that overthrew the South American country's government.
Chilean Judge Mario Carroza ordered an investigation into Neruda's death in June, noting that police, witness and medical records would be examined, Chile's judicial authority said.
The judge has not said whether Neruda's body will be exhumed.
A biography of the poet on the website of the Neruda Foundation, which Neruda's widow founded to promote and preserve his legacy, notes the coup as a significant date in his life.
"The majority of Neruda's friends were made prisoners or had to hide or seek political asylum in other countries," it says.
But the foundation's leader told Radio Bio-Bio this week that the organization opposed the exhumation because they did not believe there was a "third party" involved in Neruda's death.
"We are against an exhumation of his cadaver because it would seem to us a true act of desecration," Juan Agustin Figueroa said.
Neruda, a member of Chile's Communist Party, was also a lawmaker in the South American country and served as its ambassador to France.
But internationally, he is most well known for his poetry.
Neruda received the Nobel Prize in Literature 1971 "for a poetry that with the action of an elemental force brings alive a continent's destiny and dreams."
As part of a massive investigation of 726 reported human rights violations during Gen. Augusto Pinochet's rule, authorities exhumed former Chilean President Salvador Allende earlier this year.
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, Chile's Legal Medical Service confirmed that suicide was the cause of Allende's death.
CNN Chile contributed to this report.