A US judge has agreed to let five additional Bill Cosby accusers give evidence at his April 2 sexual assault retrial, giving prosecutors a chance to portray the man once known as America’s Dad as a serial predator who made a sadistic habit of drugging and molesting women.

Judge Steven O’Neill said prosecutors could choose the witnesses from a list of eight women whose allegations date to 1982.

Prosecutors had wanted to have as many as 19 women give evidence about alleged assaults over a five-decade span.

Among the women who could enter the witness box is model Janice Dickinson, who suspects Cosby drugged and raped her while she was unconscious during a 1982 trip to Lake Tahoe.

Janice Dickinson has made claims against Bill Cosby (Nick Ut/AP)
Janice Dickinson has made claims against Bill Cosby (Nick Ut/AP)

“We are reviewing the judge’s order and will be making some determinations,” district attorney Kevin Steele said.

Cosby’s lawyers went to court last week to block any additional accusers from giving evidence, contending they were only needed because prosecutors were desperate to bolster an otherwise weak case.

They argued jurors should only hear evidence about the alleged 2004 assault that led to the criminal charges against Cosby, not “ancient allegations” that would confuse, distract and prejudice the jury against the 80-year-old comedian.

“It just shows how desperate they are and that this is a very weak case,” Cosby spokesman Andrew Wyatt said after Mr O’Neill made his ruling.

“Mr Cosby is innocent of these charges.”

Cosby has pleaded not guilty to charges he drugged and molested former Temple University women’s basketball official Andrea Constand at his suburban Philadelphia home in 2004.

He remains free on bail.

Pennsylvania allows prosecutors to present evidence of alleged past misdeeds if they demonstrate the defendant engaged in a signature pattern of crime.