Sources close to the probe have told ITV News that the arrest is a result of the photofit released in November. The arrest is the first of a number of the arrests and is believed to be critical to the investigation, the sources said.
More top news
Tony Kim, who taught accounting at Pyongyang University of Science and Technology, was detained as he tried to leave the country.
Southern England will start dry and bright, and sunnier, colder weather will arrive in the north later in the day.
Drivers caught speeding excessively can now expect fines starting from 150% of their weekly income.