Prime Minister Najib Abdul Razak came public today to strenuously deny any involvement in the murder of Mongolian woman Altantuya Shaariibuu in 2006.

He said this after former premier Dr Mahathir Mohamad last week asked who gave the police commando, assigned to Najib as boydguards, the orders to kill Altantuya.

"This is a story from 2008 (sic), long ago. I have taken a religious oath [...] that I did not know Altantuya and I am not involved at all, directly or not. And the police have investigated," he said.

"There is no evidence at all to say I knew Altantuya. None at all...no pictures, no writings, no witnesses and all that.

"The court process went to the Federal Court. Why do want to question the integrity of the court?" he asked.

He said this in a pre-recorded interview with TV3 that was aired at 10pm.

However, the interviewer did not raise the most important question raised by Mahathir: Who ordered the two police commandos, who were at the time part of Najib's security detail, to murder Altantuya.

In a blog post last week and again during a forum last Saturday , Mahathir had said it was not fair to sentence fugitive police commando Sirul Azhar Umar to death, if the latter was just following orders.

Sirul had told Malaysiakini in an exclusive interview that he had acted under orders and those with a motive to kill Altantuya were still free.

He is currently under detention in Australia but still have access to communication devices. He fleed Malaysia before his conviction was upheld by the Federal Court in January.

Sirul and Azilah Hadri were convicted of murder and sentenced to death without a motive being established.