The bail application was heard in the High Court in Belfast
A County Antrim man accused of sexually assaulting his two daughters, taunted one about his new teenage girlfriend, a High Court bail hearing was told.
Prosecutors said the man's brother described him as "a psychopath" and warned he would kill his wife and children if released from custody.
The 46-year-old, who cannot be named for legal reasons, faces 10 counts of sexual assault against the schoolgirls.
Refusing bail, the judge said he could pose a grave risk to his family.
The accused was arrested and charged after his estranged wife told police earlier this month that he had been touching the elder daughter.
Teenage girlfriend
It was later alleged by the girl that on one occasion her father walked up behind her, grabbed her by the chest and asked inappropriate questions.
He also told her that his teenage girlfriend was "bigger" than her, according to the prosecution.
His younger daughter also claimed he had put his hand down her top, the court heard.
Crown counsel Nicola Auret disclosed that the man's brother made a statement to police claiming that if the accused was released on bail he would immediately seek out his family.
In it he stated they were terrified of him and that "nobody knows his limits".
He added: "I would be happy to stand up in court and say he is a psychopath."
Touching
Charles McCreanor, defending, said his client claimed his ex-wife threatened to "put him away for a long time" by alleging rape after he refused to get back together with her.
"The applicant would say he felt that the children were siding with the mother," Mr McCreanor said.
"It was in that context that approximately two weeks after that this allegation of touching the children came to light."
But the judge stressed he would not contemplate releasing the accused.
Mr Justice Treacy said: "This is the first case I have ever been involved in, either as a judge or counsel, that somebody's brother is prepared to make a statement to police that his own brother would do these things.
"He has expressed it not in terms of a possibility but almost in terms of an inevitability that if released on bail this applicant would kill his wife and children and anybody who gets in his way."
