The infamous paedophile killer will not be allowed to leave Ashworth Hospital in Merseyside after a tribunal ruled he remained mentally ill and his continuing disorder required medical treatment for the safety of himself and others.
Terry Kilbride, whose brother John was snatched in November 1963 aged 12, said Brady should stay in hospital.
"He should stay where he is, that's my honest opinion on it," he said. "I don't believe he's going to kill himself, that's just a ploy, just another wind-up."
He added that Brady, 75, should be kept alive as long as possible so that he could say where he had buried Keith Bennett, another of his five victims whose body has not been found.
Keith's mother, Winnie Johnson, died last August aged 78 after she had made repeated pleas to Brady to reveal the location of his grave.
Her solicitor, John Ainley, said she would have been "stressed and angry" at Brady's references to his murders as "recreational" and an "existential experience" during the eight-day hearing but would have been satisfied with the ruling.
"She always felt that Ian Brady did not give the children any choice and consequently he should not have the choice to leave the hospital environment," he said.
The tribunal was the first time Brady has been seen in public since the 1980s, when he was taken back to Saddleworth Moor in the search for the bodies of two of his victims, and the first time he had spoken in public since being jailed for life at Chester Assizes in 1966.
The decision on Brady's appeal was given by the three-person panel headed by Judge Robert Atherton, who heard the tribunal at Ashworth that was relayed to the public and press at Manchester Civil Justice Centre.
He said: "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 decision will be given at a later date.
In response, Dr David Fearnley, medical director of Mersey Care NHS Trust, said: "Ashworth Hospital has been subject to in-depth scrutiny and the public has been able to see at first hand the quality of care which we offer to all of our patients.
"Mr Brady suffers from a severe personality disorder and a mental illness which still require high quality care. It is a testament to the staff of Ashworth Hospital that we have been able to stabilise his schizophrenia to the degree we have. However, his condition is chronic and will require this support for the foreseeable future."
Brady's legal application challenged the order made under the Mental Health Act when he was transferred from prison to Ashworth in 1985, when he was diagnosed as being a paranoid schizophrenic.
Brady's legal team argued that, despite his severe personality disorder, he is not mentally ill and therefore no longer fulfils the legal criteria for detention in hospital.
Brady has suggested that, if he is allowed to go back to a jail, he would be "free to end his own life" by starving himself to death.
He has the right to challenge the decision and can apply for a fresh tribunal every year.
The estimated £250,000 cost of the tribunal, where Brady received legal aid, has been criticised as a waste of taxpayers' cash.
The tribunal heard that Brady, who claims to have been on a hunger strike since 1999 and is fed through a tube in his nose, in fact eats toast and soup and this is simply a "protest" rather than suicidal.
During four hours of largely rambling and incoherent evidence, Brady claimed to have used the method-acting skills of Constantin Stanislavski to feign the symptoms of mental illness to get into Ashworth in the first place.
Brady also compared himself to Jack The Ripper and reminisced about his time in prison with the likes of the Kray twins and the Great Train Robbers.
He denied eating in secret and refused to say directly whether he would try to kill himself if transferred to prison.
Brady and his partner, Myra Hindley, were responsible for the murders of five youngsters in the 1960s.
They lured children and teenagers to their deaths, with their victims sexually tortured before being buried on Saddleworth Moor above Manchester.
Pauline Reade, 16, disappeared on her way to a disco on July 12, 1963 and John Kilbride, 12, was snatched in November the same year. Keith Bennett was taken on June 16 1964 after he left home to visit his grandmother, Lesley Ann Downey, 10, was lured away from a funfair on Boxing Day 1964, and Edward Evans, 17, was killed in October 1965.
Brady was given life at Chester Assizes in 1966 for the murders of John, Lesley Ann and Edward.
Hindley was convicted of killing Lesley Ann and Edward and shielding Brady after John's murder, and jailed for life.
In 1987 the pair finally admitted killing Keith and Pauline.
Both were taken back to Saddleworth Moor in 1987 to help police find the remains of the missing victims but only Pauline's body was found.
Hindley died in jail in November 2002, aged 60.