North Korea must understand that Malaysia is bound by its own laws in investigating the death of Kim Jong Nam, the older half-brother of North Korean leader Kim Jong Un, said Datuk Seri Najib Tun Razak.

The Prime Minister said Malaysia had no reason to paint North Korea in a bad light.

"Our police and doctors are very professional and I have absolute confidence that they are very objective in whatever they do," he said when approached by reporters after opening an international forum here today.

Najib was was asked to comment on a North Korean proposal for a joint investigation with Malaysia into the murder of Kim Jong-nam.

North Korea's Ambassador to Malaysia, Kang Chol, said the proposal was made after "so many questions and contradictions" had arisen from the ongoing investigation into the death of Jong-nam.

On Feb 13, Jong-nam, who was estranged from his half brother, was at the KL International Airport 2 at 8am to board a flight to Macau when a woman suddenly covered his face with a cloth laced with what is believed to be poison.

Jong-nam, who was using a passport bearing the name Kim Chol, sought help at a customer service counter at klia2 and was rushed to the Putrajaya Hospital but died on the way.

-- BERNAMA