Police have identified new suspects in the murder of Kim Jong-nam, said inspector-general of police Khalid Abu Bakar.

He declined to reveal their identities or how many more suspects have will be nabbed, Bernama reported.

"I don't deny that there are new individuals, including North Koreans, who are involved in this murder and we will use all legal avenues to apprehend them.

"But I cannot reveal who they are, except to say that we believe one of them is an important person," he told reporters after officially opening an event in Malacca today.

Two foreign women have claimed trial to the charge of murdering Jong-nam, the half-brother of North Korean supreme leader Kim Jong-un, using the nerve agent VX at KLIA2 on Feb 13.

Transparent investigation

Meanwhile, Khalid said police are still waiting for assistance from North Korea to apprehend its four citizens suspected involved in the case.

Rhi Ji-hyon, 33, Hong Song-hac, 34, O Jong-gil, 55 and Ri Jae-nam, 57 are believed to be in Pyongyang.

"If North Korea does not assist us we will review other laws which can used to arrest the four suspects.

"This is a criminal matter. Don't mix it up with political issues. We are investigating a murder that happened in this country so it is our obligation to investigate transparently in accordance with existing laws," the national newswire reported him as saying.

The case has strained diplomatic ties between Malaysia and the republic, culminating the countries imposing travel bans against each other.

There are nine Malaysians - three diplomatic staff and their families - in North Korea affected by the ban on Malaysians from leaving the country. Malaysia has reciprocated against North Korean citizens.