North Korea's former acting ambassador to Italy defected to the South after disappearing from the mission in Rome two years ago, a South Korean MP confirmed Wednesday.

Senior diplomat Jo Song Gil vanished with his wife in November 2018 and reportedly sought asylum, while his daughter was said to have been repatriated to the authoritarian state.

About 30,000 North Koreans have fled repression and poverty under the communist regime and settled in the capitalist South, mostly by first secretly crossing over the porous border with China.

Jo's whereabouts remained a mystery until South Korean broadcaster JTBC reported he had come to the country.

Jo "arrived voluntarily in the South in July last year", said Jeon Hae-cheol, head of the parliamentary intelligence committee, in confirmation of the report.

Senior diplomat Jo Song Gil disappeared from Pyongyang's mission in Rome two years ago
Senior diplomat Jo Song Gil disappeared from Pyongyang's mission in Rome two years ago AFP / Alberto PIZZOLI

He had wanted his arrival to be kept secret because "he was concerned for his family remaining in the North", Jeon was quoted as saying by Yonhap news agency.

Jo is the highest-ranking North Korean official to defect to the South since 1997, when Hwang Jang Yop, once the North's chief ideologue and former tutor to previous leader Kim Jong Il, flew to Seoul from Beijing.

Italy is an important diplomatic mission for Pyongyang, as it handles relations with the Rome-headquartered United Nations Food and Agriculture Organisation.

Jo was posted to Rome in 2015 and was appointed acting ambassador in October 2017, after Italy expelled his predecessor Mun Jong Nam to protest against a nuclear test by Pyongyang.

Another high-profile defector, Thae Yong Ho, who fled his post as the North's deputy ambassador to Britain in 2016 and was elected a South Korean opposition MP in April, expressed concerns over possible retribution against Jo's family in the North by Pyongyang.

"To former North Korean diplomats who have their families in the North, disclosing their whereabouts is a serious humanitarian matter linked to the fate of their children," he said in a statement.