Two fires began on stricken sub

The crippled Chicoutimi was towed in to the Faslane naval base

Two separate fires broke out on a Canadian submarine days after it was handed over by the Ministry of Defence.

A major fire started in the commanding officer's cabin of HMCS Chicoutimi and a smaller one started in an oxygen generator, an investigation has found.

The submarine drifted for days off the west coast of Ireland after the fire, which killed one crewman and seriously injured two more.

Board of inquiry president Commodore Dan Murphy said it was "startling".

He said: "This was a major fire. There were, in fact, two fires - one of a lesser degree - and three locations were involved."

The larger fire spread through the commanding officer's cabin on the second deck and an electrical panel below it.

Weather hampered rescue

The smaller fire started in an oxygen generator 50ft away from the captain's cabin.

Commodore Murphy added: "We don't know the relationship at this point. But it was clear to me there were two separate fires, possibly from separate sources."

The five people on the inquiry board are to call on legal, medical, technical and public affairs advisers.

A five-day rescue operation hampered by high winds and waves began after the alarm was raised on 5 October that a fire had broken out on HMCS Chicoutimi.

Three men were airlifted to hospital from the submarine, which was left drifting without power about 120 miles off the Irish coast.

The fact-finding has begun. It is an administrative inquiry, it's not about blame Commodore Dan Murphy

One, Lieutenant Chris Saunders, died from smoke inhalation, and two other crewmen were seriously hurt.

HMCS Chicoutimi was decommissioned in the early 1990s. It was then refitted by BAE Systems before being recommissioned for service in the Canadian Navy.

The fire has prompted Canadian opposition parties to accuse their government of buying "inferior submarines" on the cheap.

But UK Defence Secretary Geoff Hoon told BBC Radio 4's World this Weekend programme that the vessels had been brought up to Royal Navy standards.

Commodore Murphy said they would begin sifting through documents such as sailing and technical orders and the ship's log, and said a fire investigation expert had begun examining the vessel.

He added: "Make no mistake, this is an inquiry and investigation to uncover the facts, and recommendations following out of conclusions that are based on fact.

"The fact-finding has begun. It is an administrative inquiry, it's not about blame. It does not end up in the board pointing a finger in a disciplinary way."

But he said the inquiry could examine the way the submarine was refitted.

"If there were reactivation issues that we think led to the fire, we will have to work our way back to go into those issues," he said.