People are still wondering who issued the order to murder Mongolian translator Altantuya Shaariibuu, former prime minister Dr Mahathir Mohamad says.
Former police commando Sirul Azhar Umar's claims, Mahathir said, should be investigated to determine the hidden hand behind the gruesome killing.
"Apart from (Prime Minister) Najib (Abdul Razak) dismissing the claims as 'rubbish', there was no investigation.
"This is a human life. It would be very cruel for Sirul to die for just following orders," Mahathir said in a a blog posting today.
He said this in reference to Malaysiakini's exclusive interview with Sirul, who is currently in Australia.
In the interview, the former police commando revealed that he had merely acted under orders and that those with the motive to kill the Mongolian national were still at large.
In January, Sirul was sentenced to death, together with another former police commando Azilah Hadri for the 2006 murder.
However, Sirul fled to Australia before the verdict was delivered and he is currently in the detention of immigration authorities in that country.
The Malaysian government has yet to file an application to extradite him. Australian law forbids those facing the death penalty to be sent back to their home countries.
When Najib was quizzed on Sirul's claims, the prime minister had dismissed them as " utter rubbish " while the police refused to initiate any investigation , on grounds that there has been no new revelation into the killing.
Najib's name was dragged into the case after his confidant Abdul Razak Baginda, who admitted to having an affair with Altantuya, was charged with abetting in her murder.
However, he was freed of the charge, without being called to make his defence.
Speculation continues to be rife that Altantuya's murder, and the blowing up of her body with the highly restricted C4 explosives, was related to the Scorpene submarine deal that was made during Najib's tenure as defence minister.
Najib, who was also deputy prime minister at that time, has denied any involvement with Altantuya and he has been cleared by the police.
In his blog posting, which comes on the eve of Najib celebrating his sixth year in office, Mahathir described the Scorpene submarine purchase as a "scandal".
On Monday, Law Minister Nancy Shukri said there was insufficient evidence to pursue any appeal against Razak Baginda's discharge.