The Yorkshire Ripper has said he never attacked or murdered any men in answer to questions about two unsolved cases.
Peter Sutcliffe, 71, was asked about the cases of Fred Craven and John Tomey by ITV News Calendar and wrote the letter to presenter Christine Talbot in reply.
In the two-page note, the former lorry driver, serving 20 life terms for murdering 13 women and attempting to kill seven more, denied involvement in the attacks on the two men.
Sutcliffe, who was registered blind but believed to have recently undergone laser eye surgery to save his sight, dictated the handwritten letter to a fellow prisoner at HMP Frankland, Co Durham.
He was replying to Ms Talbot after the regional news programme asked the serial killer a number of questions about the cases of Mr Craven and Mr Tomey.
Bookmaker Mr Craven was fatally wounded with a hammer in his Bingley town centre office in 1966. Leeds taxi driver Mr Tomey survived a hammer attack by a passenger as they drove across moors near Bingley in 1967.
In his letter, Sutcliffe, from Bradford, said: “I can tell you with 100% honesty I did not murder Mr Craven. And never have I attacked a male.
“Yes I did some bad things but I just want people to know I did not attack or murder any males.
“And with a whole life sentence I’d have nothing to lose and it would not be in my interest to say I didn’t do it if I did as I’m in jail till my dying day. So I’m telling you 100% it was nothing to do with me.”
Earlier this year, West Yorkshire Police said they were continuing to review historical unsolved cases linked to Sutcliffe in the 1982 Byford Report.
Sutcliffe said he had recently been questioned about 16 non-fatal attacks and police were satisfied he was not involved in any of the cases. He added he had not been questioned about Mr Craven and Mr Tomey.
Det Supt Jim Dunkerley, said: “West Yorkshire Police continues to review all undetected homicides and serious sexual offences to look to bring offenders to justice in the hope of bringing closure for victims and/or their families that they rightly deserve.”
Sutcliffe, who uses the name Peter Coonan, attacked his victims, most of whom were prostitutes, and mutilated and beaten to death, between 1976 and 1981.
He was diagnosed with paranoid schizophrenia following his life sentence but was moved to Frankland Prison from Broadmoor psychiatric hospital last year after a ruling he was sane enough to be transferred.