International investigators on Saturday said that Chilean poet and politician Pablo Neruda did not die of cancer, AFP reported. However, they could not conclusively determine if he was assassinated by late dictator Augusto Pinochet’s regime.

Neruda, a Nobel Prize laureate, died on September 23, 1973, at the age of 69, just days after Pinochet who was then the Chilean Army chief overthrew President Salvador Allende in a coup. Neruda, who had been planning to flee to Mexico to organise a resistance movement, instead died in a Santiago clinic where he was being treated for prostrate cancer.

“The death certificate does not reflect the real cause of death,” Aurelio Luna said at a news conference on behalf of a panel of investigators. The panel of 16 from Canada, Denmark, the United States, Spain and Chile could neither confirm nor deny that Neruda died of cancer.

“We do not have that definitive conclusion, we do not have the determination that there was indeed intervention of third parties,” said investigating judge Mario Carroza. The experts are now studying Staphylococcus aureus, a highly-infections bacteria that they discovered in 2013, to determine if it was the cause of Neruda’s death.