University of Tasmania researchers Associate Professor Greg Woods and Dr Alex Kreiss, of the the Menzies Research Institute Tasmania, said Cedric was part of ongoing research into the development of a vaccine against the highly contagious and deadly devil facial tumour disease.

In 2007, Cedric was born in captivity to parents sourced from the state's West Coast.

He was immunised with dead facial tumour cells and subsequently exposed to live tumour cells.

At the time, Cedric displayed an immunity to the disease, which may have initially protected him from developing the tumours, according to the university.

Cedric was then re-exposed to live tumour cells to determine if the immunisation had produced any long-term protection.

"Unfortunately, this was not to be the case, and in 2008 Cedric had two small DFTD tumours surgically removed," Associate Professor Woods said.

"Despite appearing healthy and with no signs of the disease for almost two years, a chest x-ray revealed tumour metastasis to his lungs.

"The decision to euthanise him was made last week."

Dr Kreiss said that despite contracting the disease, Cedric had provided vital information about developing a cure.

"Cedric has played an important part in helping us to understand more about the disease," Dr Kriess said.

"While this death is sad news, it is only one part of the puzzle toward developing a vaccine against DFTD.

"This was always going to be a long and difficult task but the information that Cedric supplied has provided clues for alternative immunisation strategies."

DFTD has now been recorded in devil populations across 60 per cent of the state.