North Korean diplomat, Jo Song Gil, who was until recently acting ambassador to Italy, disappeared with his wife after leaving the embassy without notice in early November, according to Kim Min-ki, a South Korean lawmaker who was briefed by the National Intelligence Service.
Earlier on Thursday, the JoongAng Ilbo newspaper, citing an unidentified diplomatic source, said Jo, 48, had applied for asylum to an unspecified Western country and was in a "safe place" with his family under the protection of the Italian government.
A senior diplomatic source in Rome said Italy's foreign ministry knew nothing about the reports. A second diplomatic source said the ministry had no record of Jo seeking asylum in Italy. The source added that North Korea had announced in late 2018 that it was sending a new envoy to Rome.
"It was a perfectly normal procedure," the source said.
Kim told reporters he had some information about the case but could not discuss it.
"They left the diplomatic mission and vanished," Kim said, referring to Jo and his family.
If confirmed, Jo would join a slowly growing list of senior diplomats who have sought to flee the impoverished, oppressive North under the rule of Kim Jong-un.
Thae Yong Ho, the North's then deputy ambassador to Britain, defected with his family to South Korea in August 2016, becoming the highest-ranking diplomat to do so.
Jo took up the acting envoy post in October 2017 after Italy expelled then-ambassador Mun Jong Nam in protest over North Korea's nuclear and long-range missile tests in defiance of U.N. Security Council sanctions.
Jo's stint began in May 2015 and was due at the end of November, lawmaker Kim said.
A source familiar with the matter, who asked to remain unnamed in order to speak about a sensitive political issue, told Reuters that Jo was officially replaced as acting ambassador by Kim Chon in late November.
The source could not confirm the JoongAng Ilbo report or whether Jo was still based in Italy.
South Korea's presidential Blue House said earlier on Thursday it had no knowledge of the matter.
Italy said in a report it submitted to a UN panel monitoring the enforcement of sanctions in November 2017 that four diplomats were stationed at the North Korean embassy there, listing the acting envoy as first secretary.
The JoongAng Ilbo said Jo was with his wife and children. Citing an unidentified expert, it said he was known to be the son or son-in-law of a top-ranking North Korean official.
North Korea forced diplomats stationed overseas to leave children at home after Kim took power in late 2011.
Thae, the former deputy ambassador to Britain, said in his 2018 memoir that was the main reason behind his defection, calling it a "hostage" scheme.
However, Thae also wrote there were some exceptions for those from the top echelons and who were seen as the most loyal to Kim.
By Hyonhee Shin and Joyce Lee/Reuters
Reporting by Hyonhee Shin, Joyce Lee and Josh Smith; Additional reporting by Crispian Balmer in Rome; Editing by Robert Birsel and Gareth Jones.