A worn pressure valve that had never been checked for 23 years has been noted as the cause of a dramatic ferry blaze.

The P&O Pride of Canterbury hit the headlines on Wednesday, September 29 last year after a fire broke out in the engine room.

But today, an accident investigation report published by the Marine Accident Investigation Branch has revealed more details.

It said that when the ship was approaching Calais at about 8am it became apparent that the starboard controllable pitch propeller was not responding.

But because of the weather conditions, the captain made the decision to carry on to the berth.

As it got closer the system ruptured, spraying oil on the exhaust uptakes and subsequently causing a fire.

Scores of French police and firefighters helped it to the shore.

The main engine room was evacuated and 337 passengers were mustered to the emergency stations.

There was 119 crew members on-board.

Pictures were taken on the smoke billowing up through the decks.

The report said: "The failed joint, along with others in the system, was not shielded to prevent a spray of oil in the event of joint failure.

"The back pressure valve was found to be worn and had not been tested for functionality during its 23 years of service."

The ferry firm has since completed a programme of modifications to the vessel and three of its other ships.

A technical bulletin has also been released which says that back pressure valves should be replaced after 15 years.

Helen Deeble, the chief executive of P&O Ferries, said: “As the report makes clear, we have already implemented a programme of modifications on the Pride of Canterbury and its sister ships to ensure enhanced safety arrangements are in place.

"We also complied with all technical guidelines that were in place at the time.

"This incident occurred as passengers were disembarking the ship, the response of our crew was immediate in successfully extinguishing the fire, and nobody was injured.

"The safety of our customers is our absolute priority and we review our procedures continuously to ensure that they are second to none.”