North Korean Ambassador to Malaysia Kang Chol was rude in his comments on the murder of Kim Jong Nam, elder half-brother of North Korean leader Kim Jong Un, said Defence Minister Datuk Seri Hishammuddin Tun Hussein.

He said Kang Chol's actions had "exceeded his responsibilities as ambassador".

Hishammuddin was asked to comment on Kang Chol's allegations that Malaysia was trying to hide something and was in cohorts with its "enemies" in the investigation of the case.

"To me, it's some diplomatic irregularity and I think the ambassador was rude in his comment on the matter. As a former Home minister, I believe that all the investigations with regard to the matter are in the good hands of the police," he said.

Hishammuddin spoke at a press conference after the return of the Nautical Aliya ship which had participated in the humanitarian 'Food Flotilla for Myanmar' aid mission, at the Boustead Cruise Centre here today.

The Malaysian Government has since dismissed the baseless allegations.

Jong-nam was at the KL International Airport 2 (klia2) at 8am on Feb 13 to board a flight to Macau an hour later when two women suddenly appeared before him and wiped his face with the palms of their hands which contained a poisonous liquid.

Jong-nam sought help at a customer service counter at the airport and was rushed to the Putrajaya Hospital but died on the way. He had come to Malaysia on Feb 6 and carried a passport bearing the name Kim Chol.

Hishammuddin said any criminal investigation was based on the laws of the country where the crime was committed and not on other laws.

He also shared his personal experience during the investigations into Malaysia Airlines Flight MH370 which went missing on March 8, 2014, and Malaysia Airlines Flight MH17 which was shot down in eastern Ukraine on July 17, 2014, when Malaysia was faced with all sorts of allegations and pressure.

"...but if we are sincere, and have facts and evidence, then nobody can accuse us of abusing our powers or not taking action to uncover the truth," he said.

On the current pressure on the nation over the investigation into the Jong Nam murder case, Hishammuddin said Malaysia did not have to worry for as long as it was on the right track.

"We stick to our stand, there is no need to falter. They (North Korea) may have a different stand, but if we are on the right track, what are we afraid of?

"We hold on to the laws of our country, our pride, our sovereignty, to uncover the truth and to find justice, that's what they (Malaysian authorities) are doing. If they (North Korea) feel this is wrong, show it to the world but they (Malaysian authorities) are just doing what they have to do based on the fact that the incident happened here," he said.