Two men who arranged the executions of Melbourne backpacker David Wilson and his two European travelling companions were themselves murdered by a Khmer Rouge commander who is serving a life sentence, new evidence reveals.
Former Khmer Rouge commander Prak Sothy says the men he identified as Vith Vorn and Bon presided over the killing of the hostages in Cambodia's mountains in September 1994 after an argument with Nuon Paet, their commander who was convicted over the kidnapping and triple murders in 1999.
Sothy says Paet argued against the executions, insisting the hostages be exchanged for $150,000 ransom payment already agreed on by the Cambodian government.

But he says Vorn and Bon, two mid-level Khmer Rouge cadres, were angry that Cambodian soldiers were attacking the mountain stronghold where the hostages were being held and took it upon themselves to execute them.
Paet, furious the men disobeyed him, ordered them killed a year later, says Sothy, whose revolutionary name was Chum Nuong.
Sothy revealed the evidence during a recent interview with Australian freelance journalist Sebastian Strangio in a village near Vine Mountain, where Mr Wilson, Britain Mark Slater and Frenchman Jean-Michel Braquet were held hostage for six weeks after being kidnapped from a train in southern Cambodia on July 26, 1994.
Victorian coroner Jennifer Coate announced in January she would reopen an inquest into Mr Wilson's death that was adjourned in 1998 after the Department of Foreign Affairs and Trade refused to hand over hundreds of documents and diplomatic cables detailing the Australian government's response to the kidnappings.
Sothy, 63, is the highest-ranking former Khmer Rouge cadre still living in the area where the hostages were held.
Speaking at his home in Chamkar Bei village, Sothy said Vorn and Bon insisted ''the three foreigners were not their parents, so they didn't care if they shot and killed them''.
Sothy said he returned to the base where the hostages were being held the morning they were killed after fighting advancing Cambodian troops.
He said his wife told him that Angkar, as the secretive Khmer Rouge was known at the time, had taken the hostages to ''a higher level'' before she heard three shots to the west of the village.
Sothy's claims appear to be backed by evidence given at the 1998 inquest in Melbourne, police reports and diplomatic cables.
The inquest heard the hostages were marched from their base where they were being held at 6am on September 8 by Vorn, Bon and five Khmer Rouge soldiers.
Chris Eaton, a senior Australian Federal Police agent who investigated the murders, testified he had interviewed witnesses who saw the hostages marched into the jungle and then heard three shots.