Deputy Prime Minister Najib Razak today brushed aside fears the high-profile murder of a Mongolian model would undermine the ruling coalition's chances in a key by-election.

The killing of Altantuya Shaariibuu, 28, rocked Malaysia because of the gruesome nature of her death and the alleged involvement of prominent political analyst Abdul Razak Baginda - whose connections extend to Najib.

The deputy premier has refused to comment on the murder since her remains were discovered in November last year.

But in some of his first remarks on the case, Najib today said he was not worried opposition parties would exploit the connections in campaigning for a key by-election next week in western Selangor state.

"I think it is alright, we are not afraid of that," he told reporters.

Mongolian model Altantuya Shaariibuu, 28, was murdered in October last year and her body blown up.

Two officers from a elite police unit have been charged with the killing, while Abdul Razak has been charged with abetting in the crime.

Anwar Ibrahim, former deputy premier and advisor to the opposition People's Justice Party, has called for a probe into the murder to determine whether Abdul Razak used government connections to organise the crime.

"I have got the option to sue but what's important is to let the law take its due course," Najib said, when asked if he would sue Anwar.

'They are telling lies'

Asked if he was denying his involvement in the crime, Najib said he would not answer to avoid prejudicing the case due to be tried on June 4.

"Whatever I said yesterday was within the bounds of the law. I don't want to go beyond that," he said.

Najib on Wednesday had said he was ready to face any allegations over his involvement in the crime and accused opposition politicians of trying to smear him.

"They are telling lies," Najib was quoted as saying in the New Straits Times in comments confirmed to AFP by an aide.

Abdul Razak, who is married, in January admitted to having an affair with Altantuya, but said he wanted her out of his life after she demanded money.

Police have said the woman was kidnapped from outside Abdul Razak's home before she was killed.

Abdul Razak and the two police officers face the death penalty if found guilty.