Lisa Holland reports on the continuing mystery

One-tenth larger than her more famous sibling, the Britannic which served as a hospital ship in World War One launched from Belfast in 1914.

Divers shed new light on mysteries

Like her equally ill-fated sister ship, the Britannic was also supposed to be unsinkable. Its design was allegedly improved for possible defects after the sinking of the Titanic four years earlier.

But the luxury liner, which was requisitioned before its maiden voyage by the UK Government, went down in just 57 minutes, more than three hours faster than the Titanic.

Around 30 people died and 1,000 survived when the ship went down in 1916 off the Greek coast.

Simon Mills: Denies arms claim

For decades the wreck lay undiscovered until the late French underwater explorer, Jacques Cousteau, found it lying at a depth of about 120 metres in 1975.

For many years, historians have argued whether the ship was hit by a torpedo or struck by a mine.

The reason why the Britannic sank in the Aegean Sea remains unresolved, but new findings have shed new light on the mystery.

An international team of divers who have been exploring the wreck have formulated different opinions and have found no evidence to suggest she was torpedoed.

"I think it probably did hit a mine," said expedition leader Nick Hope. "But to conclusively prove that it did, you would have to find the anchor chain on the sea-bed."

Wartime claims that the hospital ship was secretly transporting arms were also laid to rest.

The ship's floor remains in good condition

Owner of the wreck, Simon Mills, said: "There have been a lot of innuendoes about the Britannic since it sank.

"The Germans would have claimed for war propaganda reasons that the ship might have been transporting illegal weapons, but the divers have not found anything."

The first ever full-scale survey of the Britannic took place last year.

The ship's immense wooden deck, doors and storage rooms were found to be totally intact, although its furniture had perished.