The child killer makes other claims in the seven page letter including the fact he says he killed two men in his native Glasgow and then killed a man and a woman in Manchester.
A letter in which Moors Murderer Ian Brady claims to have killed four more people has been published for the first time, on the Daily Telegraph website.
In the seven page letter, written by Brady in 1989, he said he killed two men in his native Glasgow and then killed a man and a woman in Manchester, where he and his partner Myra Hindley abducted and murdered five children in the 1960s.
But Greater Manchester Police said the claims have been thoroughly investigated and found to be "completely unsubstantiated".
Ashworth Hospital medical director Dr David Fearnley welcomed the decision from Ian Brady's mental health tribunal to keep him in the high security hospital.
He said: "We appreciate the time and effort the mental health tribunal has taken in considering this quite extraordinary case and its judgement that Ian Brady will remain on at Ashworth Hospital is consistent with the advice our expert clinicians gave.
"This means Ian Brady will remain in the right place to receive the right treatment by the right people.
"Ashworth Hospital has been subjected to in-depth scrutiny over the past two weeks and the public has been able to see at first hand the quality of care that we offer to all our patients.
"Ian Brady suffers from a severe personality disorder and a chronic severe mental illness.
"However, he still requires high quality specialist care".
Ian Brady's mental health tribunal concluded:
The Tribunal has concluded that Mr Ian Stewart Brady continues to suffer from a mental disorder which is of a nature and degree which makes it appropriate for him to continue to receive medical treatment and that it is necessary for his health and safety and for the protection of other persons that he should receive such treatment in hospital and that appropriate medical treatment is available for him.
The reasons for the Tribunal's decision will be announced in due course.
Moors murderer Ian Brady has been told he cannot be transferred to prison from the maximum security hospital where he is being held.
Brady told his mental health tribunal he is not psychotic or insane and should be allowed to serve the rest of his whole life term in prison.
Officials at the high security Ashworth Hospital argue that he is also a paranoid schizophrenic who still shows signs of chronic psychosis.
Moors Murderer Ian Brady will find out today if he can be transferred to prison. The 75 year old who buried his victims on the moors over Yorkshire, is being force-fed at Ashworth secure hospital, but is asking the courts to move him to jail where he can starve himself to death.
Nathalie Lieven QC has been presenting her closing arguments on behalf of Ian Brady at his mental health tribunal.
She's arguing that he is sane and can be safely transferred back to the mainstream prison system.
She says he shows little sign of psychosis. His "paranoia", she says, is based on malevolence and a desire to blame others for his situation.
It stems from an incident in 1999 when he was forcibly restrained by hospital staff.
His only psychotic episode was twenty years ago, she says. No-one else would be treated like this, she argues.
He doesn't present a risk to others, she says, he hasn't attacked another patient since 1998.
She can't guarantee he won't relapse, but says if he does, he can easily be returned to hospital.
It's been 47 years since the public heard Ian Brady speak in detail - today the man who buried his victims on the moors above Yorkshire has been answering questions about his crimes and life behind bars.
The child killer's been giving evidence by video link to a tribunal in Manchester which will decide whether he's sane and can be transferred from a secure hospital to a prison. Ashley Derricott's been following the proceedings.
A forensic psychologist has questioned Ian Brady over whether his supposed psychotic symptoms displayed in the 80s were really just acting, as he has claimed.
In response to Dr Cameron Boyd's question, Brady said: "I have made this clear repeatedly. Stanislavski. Any informed person would grasp the meaning immediately."
Dr Boyd, who is also a member of the panel of the mental health tribunal, said: "Can you just explain about Stanislavski and method acting?"
Brady said: "I thought everybody knew.....It's attempting to portray the heart and soul of the character you are trying to portray."
Ian Brady is rambling through the afternoon session of his mental health tribunal.
He's talking about what he describes as "recreational killing".
"I'm as pragmatic as a soldier or a politician", he said. "You don't see any regret from Tony Blair, in fact he's making a fortune from his war crimes."
"I'm a comparative petty criminal to global serial killers like Blair and Bush," he added.
He said the moors murders were an "existential experience" for him.