Dana's brother told the mother of a girl he is accused of indecently assaulting that he had been cured of his problems as long as he would "eat well, sleep well and watch for the signs".
The mother said John Brown (60) had told her that God had forgiven him and it was time for her to do the same.
The comments came yesterday at the second day in the trial of Brown, of Lilly Hill Road, Bracknell in Berkshire, who has denied five counts of indecent assault against two children at various dates in the 1970s.
Brown is the brother of Londonderry's former Irish presidential candidate and Eurovision winner Dana Rosemary Scallon.
The first alleged victim says she was assaulted by Brown twice in the UK and twice in her home in the US. The second two alleged incidents are not included in this case.
The mother of the alleged victim said her daughter told her about what she said happened after the third incident, when she was aged 10 or 11.
The mother said she had confronted Brown, who claimed that her daughter had come on to him, after which the mother said she called him a "crazy b******".
She then rang Ms Scallon and told her what had happened.
The mother said that Ms Scallon said she knew a priest who could help him.
It was more than two years later when she was told by both Ms Scallon and Brown that he was healed.
"John and Dana told me that the person he was seeing had died but that he was healed and God had forgiven him and it was time for me to as well," she told the court.
"John said he had three things to do... he had to eat well, sleep well and watch for the signs and as long as he did that, he was fine."
When he returned to Iowa after this, it is alleged that he assaulted the daughter of the woman again, after which time she told her mother.
It also emerged that the first alleged victim confronted Ms Scallon in a phone call at the time of the last Irish presidential election and told her that she knew what "was going on".
Ms Scallon said that she did not recall anything, according to the alleged victim, now in her 40s. "I said 'yes you do, you are my spiritual guide and you always knew'," she said, continuing that Ms Scallon said she would pray for her.
The court has heard that the alleged victim has filed a defamation suit against Ms Scallon and TV3 over comments the singer made about the allegations in the run-up to the election when she called them "vile and malicious lies".
Counsel for Brown, Martyn Bowyer, said the allegations were untrue and that the only reason she had come to police in the UK was as she had no choice as no defamation action in the Republic would be successful without a complaint to the authorities.
"No. It seems an awful lot of planning for something so hurtful," the woman said.
Brown is charged with five counts of indecent assault against two children, one of whom was under 13 and another under 16, on various dates during the 1970s.
The case continues.
Derry singer Dana's brother John Brown (60) is charged with five counts of indecent assault against two children.
One assault is alleged to have happened in Northern Ireland.
Brown was a member of Dana Scallon's election team when she ran for the Irish presidency against Michael D Higgins and Martin McGuinness in 2011.