MASS murderer Jeremy Bamber is confident he will be able to challenge his conviction at the Court of Appeal by Christmas.

The Criminal Case Review Commission (CCRC) which investigates miscarriages of justice is expected shortly to announce whether Bamber, 49, can appeal against a life sentence imposed in 1986.

If successful Bamber plans to submit a photograph of a silencer, or sound moderator, that has appeared in Chronicle news pages.

The picture, taken at a police press conference shortly after his conviction at Chelmsford Crown Court, shows a silencer lying detached beside the .22 Anschütz semi-automatic rifle.

It was the prosecution's case that Bamber attached the silencer to the rifle when he killed his adoptive parents, June and Neville Bamber, his sister Shiela Caffell and her twin six-year-old sons, Daniel and Nicholas at White House Farm, Tolleshunt D'Arcy.

Bamber said: "Your photograph is excellent as I only have a poor photocopy of a silencer provided by Essex Police.

"The Chronicle's picture shows one end of the silencer while the opposite end is hidden, but my defence team will now use cutting-edge imaging technology to create a view of the other end, which could turn up something to help prove my innocence."

He claimed Essex Police had been able to prevent him from seeing any of the 211 key photographs because of public interest immunity imposed by the Home Office.

Bamber was initially jailed for 25 years, but then Michael Howard later ruled that he would never be released.

Having served more than 23 years he continues to maintain his innocence of the slayings.

Bamber, writing exclusively from HMP Full Sutton, York, stated: "Your photograph could help toward proving my innocence because the jury was fooled into thinking only one silencer was discovered at the farm. Two were found at different times."

During his trial, the jury at Chelmsford Crown Court handled the rifle and heard that the silencer was found to contain splashes of Sheila Caffell's blood.

The trial learned that a silencer was found in a gun cupboard by a relative days after police left the scene.

Bamber commented: "The prosecution claimed the (second) moderator had allegedly made scratch marks on a kitchen mantle shelf above the Aga, but those marks occurred something like a month later. Scenes of crime photographs show no scratches to the mantle or flecks of paint on the carpet below."

Essex Police initially believed model Sheila, nicknamed Bambi, had indeed "gone crazy" before shooting herself and gave the go-ahead for cremation following the funeral at the parish church.

But the subsequent discovery of a blood-stained silencer in the farmhouse made this theory implausible.

Bambi could not have killed herself as the addition of the silencer would have made the rifle too long to pull the trigger and anyway the silencer was found downstairs.

Bamber told the Chronicle that one of Britain's most eminent photographic experts had examined police negatives and concluded they were "incompatible" with the principal prosecution case.