KUALA LUMPUR, Dec 16 — Authorities must investigate the shocking allegations of Datuk Seri Najib Razak’s purported order for the 2006 murder of Altantuya Shaariibuu without fear or favour, the lawyer for her family said today.

Ramkarpal Singh, who is also DAP national legal bureau chairman, referred to the contents of a statutory declaration by former police commando Azilah Hadri who had been convicted and sentenced to death along with Sirul Azhar Umar for the murder.

"In the said SD, Azilah claims to have been ordered by former Prime Minister Najib Tun Razak, with the knowledge of Razak Baginda and senior police officer DSP Musa Safri, to kill Altantuya and dispose of her remains,” Ramkarpal said in a statement today, referring to Najib’s former aide Razak Baginda and Najib’s former aide-de-camp Musa.

"If such allegations prove to be true, there must be a prosecution against those involved despite Azilah and Sirul Azhar Umar having been convicted by the Federal Court for the said murder as there is no limitation period in criminal cases and one can be prosecuted for an offence despite a long time lapse, provided there is evidence to support such prosecution,” he added.

Ramkarpal said Altantuya’s family had for years demanded a thorough investigation on who gave orders for the 2006 murder, noting that both Azilah and Sirul had "no possible motive” for killing her.

Ramkarpal said the police do not need to wait for a police report to be lodged on Azilah’s statutory declaration before carrying out investigations, as the police can act on the document itself.

"A fresh statement must be taken from Azilah himself now and those he had implicated in his said SD, including Najib and I urge Inspector General of Police Hamid Bador to do so forthwith in light of the seriousness of the said allegations.

"The mystery of who ordered the murder of Altantuya is one that must be eventually resolved and today’s development may be an important step in that direction,” the Bukit Gelugor MP added.

Ramkarpal said Altantuya’s family "will not rest until the motive and personalities behind her brutal murder is revealed and those responsible are brought to justice”.

Noting that Azilah had made the statutory declaration to support his application to the Federal Court for a review of his conviction and death sentence, Ramkarpal said Altantuya’s family will apply to the court to hold a watching brief in that matter.

Ramkarpal said Altantuya’s family’s ongoing civil lawsuit in the High Court in Shah Alam will also be amended to include the new allegations from Azilah’s statutory declaration and the resulting findings of the police investigation on the matter.

News portal Malaysiakini which had reported and reproduced the contents of the statutory declaration, had also reported of Najib’s asserting his innocence and dismissal of Azilah’s claims as purportedly being a "complete fabrication".

Azilah has been on death row since 2015 following the Federal Court’s decision to reinstate his death sentence, while Sirul is currently in Australia which he had gone to before the Federal Court delivered its decision.