Notorious serial killer Ivan Milat has written to the media from Long Bay jail hospital, claiming he is innocent of the murder seven backpackers.

In a three-page handwritten letter dated July 11 and sent to The Sun-Herald, the 74-year-old says his life since being arrested and convicted “has been devoted wholly to prove my innocence…(and) the court judiciary who conspired to obscure the miscarriages of justice”.

Milat was found guilty in 1996 of murdering seven backpackers whose bodies were found in makeshift graves in Belanglo State Forest in the 1990s.

He was transferred back to Long Bay jail hospital last weekend after spending more than a week at Prince of Wales Hospital in Randwick.

He spent another two weeks at the hospital in May when he was diagnosed with oesophagus and stomach cancer.

“I am sure that you are aware of how cancer is, it’s a grim finding and less than fifty per cent survive it and, I feel that the unpredictability of the effect of the treatment would overtake any commentary by me of it,” Milat writes in the letter published by the Sydney Morning Herald on Sunday.

“It is in the hands of my carers (doctors etc) and of course, Our Lord in Heaven.”

Despite his 1996 conviction, Milat has always maintained his innocence and unsuccessfully made an application to the High Court for an appeal in 2004.

The NSW Corrections Commissioner Peter Severin said in May he hoped Milat would talk to police during his final days, to shed light on other crimes he may have committed.

– AAP