Modifications that might have prevented a middle-of-the-night fire on a cruise ship in the English Channel were not carried out, an accident investigation report said today.

The response to the fire "highlighted flaws in the knowledge, experience and training of some of the senior ship's officers," the Marine Accident Investigation Branch (MAIB) report added.

The fire on board the Cypriot-registered vessel The Calypso off Beachy Head, Sussex, was eventually put out and the ship was towed to Southampton. No one was hurt.

The vessel was operated by the Louis Cruise line whose vessel Sea Diamond sank earlier this month after striking a reef off the Greek island of Santorini. Two French passengers are feared dead.

The Calypso was sailing from Tilbury in Essex to St Peter Port, Guernsey, on May 6 2006 with 708 people aboard including more than 460 passengers.

The fire broke out around 3.30am and was caused by a failed low pressure fuel pipe flange on the starboard main engine.

The flange bolts had failed probably due to fatigue and similar incidents "had occurred in the past and over 10 years previously", the report said.

The engine makers had issued a technical bulletin in 1995 but, possibly due to frequent changes in the vessel's ownership, that bulletin, and another updated one circulated in 1999 "were not effective in ensuring that the necessary modifications were carried out on The Calypso," the MAIB said.

It added that those in charge of the fire-fighting response "did not appear to follow recognised good practice".

Those on board thought the fire had been successfully put out by the quick use of the fixed carbon dioxide (CO2) fire-smothering system. In fact the fire had died down mainly as a result of fuel starvation due to the quick action of the watchkeeping engineer officer, the report said.

The CO2 system was not checked and made secure after the fire, and it had been left in a dangerous condition.

The MAIB went on: "During the investigation into the cause of the fire, after the vessel's arrival in Southampton, CO2 from a bank of cylinders was accidentally released into the engine room. In the event, three crew were lucky to escape without loss of life or serious injury."

The report added: "Despite most passengers being elderly, and the cold temperatures experienced out on deck at night, it is to the credit of the master and the crew that nobody suffered anything more than discomfort."