Lawyer Ramkarpal Singh said today that Prime Minister Dr Mahathir Mohamad has agreed to reopen the murder case of Mongolian national Altantuya Shaariibuu.

Ramkarpal said this after accompanying Altantuya's father Setev Shaariibuu to meet Mahathir at the Prime Minister's Office this evening.

"Mahathir agreed for the investigation into the case to be reopened, as long as it is done within the law," he told journalists after the meeting.

Ramkarpal said the purpose is to establish who instructed the murder of Altantuya, which was never explored during the murder trial.

"Whoever who ordered the killing must face the law," he added.

Setev arrived in Putrajaya at around 4.20am, and exited from the Prime Minister's Office at around 6pm.

Speaking through a translator, he said he was satisfied with the meeting.

Read more: Ex-Najib aide Musa Safri named in Altantuya murder police report

Earlier today, Setev had also lodged a police report to urge for the case to be reopened.

He named former prime minister Najib Abdul Razak's aide de camp Musa Safri – whose name emerged during the murder investigation, but was never called to testify by the prosecution.

Altantuya was murdered in 2006. Her remains were blown up with military grade explosives.

Sirul Azhar Umar and Azilah Hadri, who were attached with the Special Actions Unit, were found guilty for her murder.

They managed to overturn the conviction at Court of Appeal, but the Federal Court in reinstated their death sentence in 2015.

However, Sirul fled the country and is now being held in a detention centre in Australia.

The duo were bodyguards to Najib, who was deputy prime minister at the time.