North Korea's ambassador left Malaysia Monday, a senior government official said, after he was expelled in a deepening dispute over the assassination of Kim Jong-Nam.

Malaysia declared Kang Chol persona non grata and gave him 48 hours to leave the country after he failed to apologise for his criticism of the murder investigation, which found that the half brother of Pyongyang's leader had been poisoned with the nerve agent VX. 

"The Malaysian Airlines plane has taken off," the official told AFP, asking not to be named. He added that Kang left Malaysia at 6.25pm (1025 GMT) on flight MH360 for Beijing, shortly after the deadline for his expulsion expired.