A photograph eerily reminiscent of the grainy picture developed in the darkroom during the classic 1966 film Blow Up could hold vital clues to a suspicious death in Australia.rnrnPicture: When developed the image revealed the motionless body of Tina Watson, lying on the seabed in the background of the picture Photo credit: Rex Features

A photograph eerily reminiscent of the grainy picture developed in the darkroom during the classic 1966 film Blow Up could hold vital clues to a suspicious death in Australia.

Detectives are analysing a holiday snap captured by a scuba-diving tourist off the Great Barrier Reef, which inadvertently reveals the motionless body of Christina Mae Watson, 26, in the background.

Christina, known as Tina, was pulled from the water unconscious but later died in the 2003 tragedy.

It is understood that the photographer, whose name has not been made public, only realised the importance of the picture years after it was taken.

The inquest in Townsville, Queensland is reportedly treating the image as a crucial piece of evidence in the unexplained death of the American who married just ten days earlier.

Tina and husband Gabe had decided to go diving as part of their honeymoon.

Mr Watson, a certified rescue diver, said his wife was an inexperienced diver who panicked and got into trouble during strong currents.

He said she knocked off his face mask and breathing regulator and was unable to bring Tina to the surface.

Mr Watson has not been charged in connection with his wife?s death.

The holiday picture shows a diving instructor swimming towards Tina Watson’s body and the photographer’s friend in the foreground.

Picture: When developed the image revealed the motionless body of Tina Watson, lying on the seabed in the background of the picture Photo credit: Rex Features

Photograph at centre of honeymoon death mystery