A black Audi stolen from a driveway in Clontibret late on Sunday night was spotted heading in the direction of Derrynoose.
Police on both sides of the border have issued an appeal for help, as well as a warning for residents to be on the lookout for a vehicle “highly likely” to be involved in crime on both sides of the border.
A Gardai spokesperson said: “We are appealing this morning for information relating to the theft of a black Audi A6, 182 D, that was stolen from the driveway of a house in the Clontibret area of Monaghan at approximately 11pm last night.
“It was driven off in the Derrynoose direction heading for the border with Northern Ireland.
“A silver/green VW Passat was possibly travelling in convoy with the stolen car.
“If you observed either of these cars or anything suspicious in the area or can offer any information please contact us at Monaghan Garda Station on 047 77200.”
Police in Armagh have re-iterated that appeal.
“Please contact Police or Gardai in confidence if you have any information.
“Remember it is highly likely that this vehicle will be involved in crime on both sides of the border please report suspicious activity immediately do not delay.”