The Minister for Defence, Mr. Willie O'Dea, has confirmed that the Irish Naval vessel LE Roisín is en route to the location of a Canadian submarine which issued a distress call earlier today after a fire broke out on board.
Three crew members of the HMCS Chicoutimi, which was passing within 100 miles of Ireland's west coast, suffered from smoke inhalation.
The captain of the HMCS Chicoutimi raised the alarm shortly after 3 p.m and their calls were answered by teh RAF and the Royal Navy.
The situation on the non-nuclear traditional diesel-powered submarine is now described as 'stable', but The Roisín, which was on routine patrol off the North West coast should arrive at the scene around midnight, to offer any assistance required - including the monitoring of any threat to Irish waters, fish stocks or coastline from marine pollution.
It is understood there are about 50 personnel on board the submarine.
The British Ministry of Defence confirmed an RAF Nimrod from Kinloss was in the area while a Royal Navy search and rescue helicopter was launched from Prestwick.
The Victoria-class submarine was formerly named HMS Upholder but it was renamed and formally handed over to the Canadian navy during a ceremony at Faslane on Saturday.
The vessel had been due to arrive in Halifax, on the east coast of Canada on October 18th.
Neil Smith, the Royal Navy's regional director of communication, said: "We are responding to a request for assistance from a Canadian submarine 100 miles west of Ireland.
"We believe she had an electrical fire and there are three people suffering from smoke inhalation.
"We have dispatched a Royal Navy Sea King from HMS Gannet near Prestwick in Ayrshire.
"We have also turned round the Royal Fleet Auxiliary Wave Knight which was in the area. It is a 200-metre long fleet replenishment vessel.
"We are in the process of scrambling HMS Montrose which is a type 23 frigate which will leave HMS Clyde at Faslane at 1800 to make haste to the scene.
"I have to stress that this is a non-nuclear submarine and is powered by diesel electric motors and it was built in the early 90s."