The Royal Malaysian Police (RMP) will liaise with the Attorney-General to request and negotiate with Australia to extradite former police commando Sirul Azhar Umar.

Inspector-General of Police Tan Sri Khalid Abu Bakar said the process of bringing back Sirul Azhar, who faced the death penalty for murder, involved negotiations.

"We are aware that Australia has laws preventing it from cooperating with Malaysia...we have to overcome that first," he told reporters after launching the RMP special edition toy cars made by toy maker Daisheng (M) Sdn Bhd here Friday.

He was replying to reporters on the current status of efforts to bring Sirul Azhar back to the country.

Khalid said he could not determine a time frame for the process which could take quite long.

Sirul Azhar and Chief Inspector Azilah Hadri were charged with killing Mongolian, Altantuya Shaariibuu, a part-time model in 2006 and they were convicted by the High Court in 2009.

On Aug 23, 2013, the Court of Appeal freed Azilah and Sirul Azhar, following an appeal.

On Jan 13, this year, the Federal Court set aside the Court of Appeal ruling and restored the death sentence.

However, Sirul Azhar was not present in court to hear the sentence as he was believed to be in Australia.

The Federal Court then issued an arrest warrant for him.