North Koreas deputy ambassador in London has defected with his family, according to media reports, which if confirmed would make it one of the most high-profile defections in recent years from the increasingly isolated country.

South Koreas JoongAng Ilbo newspaper reported on Tuesday that a high-profile diplomat in the UK defected with his wife and son to a third country. The BBC named the defector as veteran diplomat Thae Yong Ho, a counsellor at the North Korean embassy and deputy to the ambassador.

Quoting an unnamed source, JoongAng Ilbo said the diplomat embarked on a defection journey following a scrupulous plan and was in the process of landing in a third country as an asylum seeker.

It was not clear from the newspaper report whether the third country was the UK. The term is usually used in South Korean media to refer to a country which is neither North nor South Korea.

An official at the North Korean embassy in London would not confirm the defection, describing reports of the event as quite sudden. If it is appropriate to give a response, then you might hear about our response, the official told Reuters.

Further calls to the embassy went unanswered. Calls to Thaes mobile phone were redirected to a voicemail inbox.

Thaes reported defection follows a string of recent such flights by North Koreans, including 12 waitresses at a North Korean restaurant in China who defected to South Korea earlier this year.