Police are looking into the possibility that one of the assassins involved in the killing of Kim Jong-Un's brother was a man who disguised himself as a woman, according to reports.

An investigation into the killing of Kim Jong-nam in what is believed to have been a poison attack at Kuala Lumpur airport suggests he was held from behind by one assailant while another sprayed him in the face with the deadly substance.

The half-brother of the North Korean leader is reported to have staggered towards an information desk and muttered "very painful, very painful, I was sprayed with liquid" before collapsing.

Three people – an Indonesian woman, a woman carrying Vietnamese travel documents and a Malaysian man – have been arrested, with police still hunting for four men believed to have been accomplices in Kim's murder.

Police are also looking into the possibility that one of the assailants is a man who had disguised himself as a woman as a distraction technique, reported the New Straits Times.

Federal Police Special Branch director Datuk Seri Mohamad Fuzi Harun added: "We have reason to believe that this [murder] might be the work of foreign agents. There are definitely other individuals involved, apart from the two assailants."

Elsewhere, Malaysian police said they will not release Kim's body unless a member of his family can provide a DNA sample. North Korea has yet to publicly comment or respond to his death.

Selangor state police chief Abdul Samah Mat told Reuters: "We are still waiting for the next of kin application, we have not received it yet. We have only received the application from the North Korean embassy yesterday.

"We need to collect DNA samples from the next-of-kin in order to get conclusive evidence on the victim's identity."

Kim Jong Nam
CCTV footage that was televised by South Korean news channel YTN, showing one of the alleged assassins YTN