Dad-of-one Ciaran Noonan was chased and assaulted by up to five men in Dublin’s north inner city at around 4.45pm on October 20 before being bundled into a car and driven away.
The 29 year old has not been seen since and has not been in contact with family or gardaí, who are very concerned for his safety.
Gardaí said Mr Noonan had owed “a couple of thousand euro” to a drug dealer based in Blanchardstown, north west Dublin, where he originally lived.
Detectives have identified the owner of the 05 Volkswagen Golf that was used in the abduction, but have not located him.
They have arrested his girlfriend on suspicion of withholding information. She and another woman who was arrested have been released without charge.
The Golf was found some three hours after the abduction at the Kellegland Apartments in Ashbourne, Co Meath.
Gardaí began searches in the Ashbourne area on Monday and yesterday concentrated on the old Trim Road between Dunboyne and Trim.
Later yesterday, they moved to another location on the Ashbourne Road and ended the search when daylight deteriorated.
Garda sources said search teams intend to examine a number of locations in the coming days.
Meanwhile, Mr Noonan’s mother Geraldine described as “callous and hurtful” reports that her son may have killed himself.
Mr Noonan is described as being of medium build with short dark brown hair and brown eyes.
When last seen he was wearing a light blue hoodie and grey tracksuit bottoms.