SEOUL, South Korea — A senior North Korean diplomat who disappeared from Italy in late 2018 has been living secretly in South Korea since July of last year, a member of the intelligence committee of the South Korean Parliament and the South’s news media said on Wednesday.
The diplomat, Jo Song-gil, then 48, was North Korea’s acting ambassador to Rome when he and his wife disappeared days before he was scheduled to return home to Pyongyang in November 2018. His whereabouts had since remained a mystery, prompting speculation that he had become one of the most senior diplomats to desert the totalitarian North.
The revelation about Mr. Jo could further aggravate North-South relations, which have been in a downward spiral for months after the North blew up a jointly run liaison office and its troops killed a South Korean government official during a sea patrol.
Diplomats’ defections are a sensitive issue for Pyongyang because they are often interpreted in the outside world as a possible sign of fraying loyalty among the privileged class. They also raise the possibility that the South Korean authorities could glean a wealth of information, especially about smuggling and other illicit ways in which North Korean diplomats earn foreign currency in violation of United Nations sanctions.
Ha Tae-keung, a member of the main opposition party in South Korea, said on Facebook on Wednesday that Mr. Jo had arrived in the South 15 months ago and remained under government protection. Mr. Ha is a senior member of the intelligence committee of the South’s National Assembly and often briefs the news media on closed-door parliamentary reports from the country’s National Intelligence Service.
Mr. Ha went public with his revelation hours after JTBC, a South Korean cable channel, reported that Mr. Jo had defected to the South. JTBC cited anonymous intelligence sources as confirming Mr. Jo’s defection, and other South Korean news outlets followed up with similar stories.
The National Intelligence Service said on Wednesday that it “will not confirm” the news reports or Mr. Ha’s statement. The agency has often used such a stock phrase when it wants to keep secret the defection of a prominent North Korean for fear of consequences in inter-Korean relations or to help protect the defector’s relatives in the North.
If his defection is confirmed, Mr. Jo will be the most senior North Korean government official to flee to the South since Hwang Jang-yop, a former secretary of the North’s ruling Workers’ Party, defected to Seoul through the South Korean Embassy in Beijing in 1997.
The last senior North Korean diplomat to defect to the South was Thae Yong-ho, a minister in the North Korean Embassy in London, who fled to Seoul in 2016 with his wife and two sons.
Over the years, some prominent North Koreans like Mr. Hwang and Mr. Thae have led public lives after their defections to the South. But many others have wanted to keep their defections secret to protect their relatives in the North, and the South Korean intelligence authorities have abided by their wishes. When its diplomats are posted abroad, North Korea requires them to leave some of their children in the North in order to discourage defections.
Mr. Jo and his wife lived with their daughter in Rome. But when they escaped, they could not bring the daughter with them. Italy later said that the daughter had been taken home by the North Korean authorities.
After Mr. Jo disappeared from Italy, Mr. Thae, who defected with his wife and all his children, issued an open letter appealing to the acting ambassador to defect to South Korea. But after Mr. Jo’s daughter was taken to the North, Mr. Thae said it would be extremely difficult for Mr. Jo to settle in the South.
“His daughter would suffer a more severe retaliatory punishment if he chose to defect to South Korea” rather than to other countries, Mr. Thae told reporters last year. “He may have to remain silent and keep his whereabouts secret to protect his daughter.”
On Wednesday, Mr. Thae, now a lawmaker affiliated with the main opposition party in South Korea, issued a statement worrying that the revelation in the news media of Mr. Jo’s whereabouts would further jeopardize the fate of Mr. Jo’s daughter in the North.
It remains unclear exactly why Mr. Jo decided to flee North Korea. He was posted in Rome in May 2015. He served as the North’s acting ambassador after Italy expelled the ambassador, Mun Jong-nam, in 2017 in protest over the North’s sixth nuclear test.
Mr. Jo’s disappearance was kept secret until a South Korean newspaper reported last year that he was seeking asylum in the West. South Korean lawmakers later briefed by the National Intelligence Service confirmed his disappearance. In August of last year, the spy agency told lawmakers in Seoul that Mr. Jo was safe “somewhere” outside Italy.
North Korea has yet to comment on Mr. Jo’s case.
More than 30,000 North Koreans have defected to the South since the mid-1990s. The North typically calls them “human scum” and “traitors,” or claims that they were kidnapped by the South Korean spy agency.
North Korea diplomats are usually children of elite families. Mr. Jo’s father and father-in-law both had been ambassadors, Mr. Thae said.