Nine Malaysians have arrived home safely from Pyongyang in a precisely timed exchange for the body of Mr Kim Jong Nam and three North Koreans suspected of being involved in his murder.

A Royal Malaysian Air Force team of six posing as commercial crew, wearing civilian clothes instead of their uniforms, flew the three Malaysian diplomats and their six family members to Kuala Lumpur on a private jet for their safety.

They had been barred from leaving North Korea since March 7.

Police insisted that investigations into the Feb 13 murder allegedly ordered by Pyongyang would not be compromised by the release of the trio of North Koreans, including a senior diplomat, who had been holed up in their Kuala Lumpur embassy since the attack.

Inspector General of Police Khalid Abu Bakar told reporters that his officers recorded their statements on Sunday at the embassy and investigators were "satisfied with the reasons they gave us" before allowing them to leave.

"We have obtained whatever we want from them. They are no longer needed for investigations. It has not been compromised."

However, Insp Gen Khalid insisted that North Korea should hand over four citizens who fled on the day the estranged half-brother of leader Kim Jong Un was killed, as they are jointly accused of murdering Mr Kim with two women who have been charged with his murder.

North Korea has denied involvement in the crime and insisted the dead man was named Kim Chol.

Early yesterday, Foreign Minister Anifah Aman greeted the nine Malaysians at the Kuala Lumpur International Airport after the tense exchange.

It appeared to be timed so their plane would be allowed to leave Pyongyang only at the exact time Mr Kim's corpse and the North Koreans left on a flight to Beijing on Thursday night.

The pilot, Lieutenant-Colonel Hasrizan Kamis, had flown missions into dangerous countries such as Libya, but the Star reported him saying he only started breathing easy after leaving North Korean airspace.

"We were not sure what to expect as we entered North Korean air space," he said after landing.

Mr Mohd Nor Azrin Md Zain, a counsellor at the Malaysian embassy in North Korea, said he and his colleagues were glad to finally be home.

In Pyongyang they had all the support that they could get, especially from Asean embassies, including Indonesia, Laos, Vietnam and Cambodia.

Said Mr Nor Azin: "We received moral support, logistics support, food supplies and medicine supplies from them."

KEY DATES IN KIM JONG NAM SAGA

Feb 13: Mr Kim is attacked by two women, allegedly with nerve agent VX, at Kuala Lumpur International Airport and dies.

Feb 15: Police arrest Vietnamese Doan Thi Huong, 28.

Feb 16: Police arrest Indonesian Siti Aisyah, 25.

Feb 17: North Korean chemist Ri Jong Chol is arrested in KL.

Feb 19: Police release images of four North Korean suspects, believed to have fled Malaysia on Feb 13.

Feb 20: Malaysia recalls its ambassador to North Korea.

Feb 28: North Korean delegation is in KL to seek release of Mr Kim's body as well as Ri.

March 1: Huong and Siti Aisyah are charged with murder.

March 3: Ri is released and deported. Kim Uk Il, Kwang Hyon Song and Ri Ji U are still wanted.

March 4: Malaysia expels North Korean ambassador.

March 6: North Korea expels Malaysian ambassador. Malaysia cancels visa-free entry for North Koreans.

March 7: North Korea imposes travel ban on Malaysians in Pyongyang. Malaysia issues reciprocal ban on North Koreans in Malaysia.

March 16: Police obtain Interpol red notice for the four North Koreans who fled on Feb 13.

March 31: Mr Kim's body and three wanted North Koreans flown back to Pyongyang. Nine Malaysians stranded in Pyongyang return to Malaysia.