Manchester Police say they are becoming increasingly concerned for Lisburn man Mervyn Craig who vanished without trace in England, almost a month ago.
Mervyn Craig (46), , has not been seen since February 8 when he left the Wigan home of a woman he had befriended online.
The father-of-four told his family he was going to Manchester for a job on a building site.
He left Lisburn on January 28.
Manchester Police say there has been no sightings of him since February 8.
Mr Craig, is a diabetic and insulin dependent requiring daily self-medication via injection from a weekly prescription. Failure to administer it could leave him disorientated and confused.
His secret relationship with the English woman was uncovered when his daughter accessed his Facebook account.
Anyone with any information on his whereabouts is asked to call Greater Manchester Police on 101.