AN investigation has been launched after claims that gardaí were trailing two men in a car a short time before they died in a horrific early morning crash in Co Donegal.

The Republic's Garda Ombudsman's office, GSOC, has confirmed it is examining an "interaction" between officers and the Mitsubishi Charisma before it was in a head-on collision while travelling the wrong way on a dual carriageway outside Letterkenny.

The two victims were members of the settled Travelling community from the town.

They were named locally as Barney McGinley (28) and Dermot Boyle (19).

Sources have claimed their car was trailed for a short time by gardaí before it went onto the dual carriageway.

They were among four people killed in three crashes within hours of each other in the Republic overnight on Tuesday.

Barney McGinley (left) and Dermot Murphy-Boyle died in Wednesday morning's accident

A 42-year-old driver also died following a head-on collision at Dunboyne, Co Meath, while a man in his 20s was killed in a crash near Kilcock, Co Kildare.

The Mitsubishi Charisma was in a collision with a Renault Master van on the N13 at Trimragh at about 4.45am yesterday.

The two victims were pronounced dead at the scene while the driver of the van, a 40-year-old man, was taken by ambulance to Letterkenny University Hospital.

His injuries are not thought to be life-threatening.

The main Derry to Letterkenny road remained closed for much of yesterday as investigations continued around the mangled remains of the two vehicles.

The Garda Ombudsman’s office said its officers were called in after the case was referred to them by gardaí.

A GSOC spokeswoman said: “It appears that there had been some interaction between gardaí and the vehicle in which the two young men were travelling prior to the collision.

“GSOC will examine the circumstances to establish the facts in this regard.”

The head of the Donegal Garda traffic corps, Michael Harrison, also confirmed that the men’s car was travelling in the wrong direction.

“It is normally a relatively quiet time but there may have been delivery vehicles or people travelling to go on shift work," he said.

"We would appeal to anybody who was on the road at the time and may have noticed a vehicle travelling in an unusual manner to come forward."