The Rosemary's Baby director is currently behind bars in Zurich, Switzerland following his arrest on Saturday (26Sep09) on an international warrant.
He is fighting extradition to the U.S., where he faces sentencing after pleading guilty to unlawful sex with a 13-year-old in 1978. He claimed the judge in the case had reneged on a plea bargain.
A host of Hollywood heavyweights have reportedly rallied to appeal for Polanski's release, including movie mogul Harvey Weinstein and director Woody Allen, and now the sister of his murdered wife Sharon Tate is stepping up to defend the star.
During an appearance on America's Today Show on Wednesday (30Sep09), Deborah Tate insisted Polanski had been wrongly jailed.
She told America's Today Show, "Roman is a brilliant director, there is no disputing that. He's also a philanthropist. He helps many other people get a foothold in the business. He's quite a humanitarian He's a good guy. He's brilliant as well."
Tate admitted she had previously tried to convince Polanski to face the consequences of his actions by returning to America in 2005, but has since realised he would never receive "fair" treatment in the U.S. justice system.
Instead, she's adamant Polanski should be allowed to be sentenced in his adopted home of France, instead of being extradited to the U.S., which he fled in 1978.
She added, "There was a deal made back in the '70s where Roman would undergo evaluation and spend four months in jail. He did that. He was evaluated not to be a paedophile and there's rape and then there's rape. It was determined that Roman did not forcibly have sex with this young woman, it was a consensual matter. I am a victim's advocate and I know the difference.
"I do believe that our system is extremely broken on multiple levels. I think at the moment there's a lot of taxpayers' dollars that are spent on cases that do not need to be pursued, especially in the state of California. It's a very multi-million dollar broken system.
"I was under the impression (in 2005) that there was misconduct in the political genre itself and based on that, perhaps he could get a fair trial here. Since then, speaking to the District Attorney's office about this matter, I agree that Roman could not necessarily be dealt with in a fair manner in the United Staes. I think that this matter better be served in France."
Sharon Tate and her unborn child were murdered in August 1969 by members of Charles Manson's notorious cult, including Susan Atkins, who died in a California prison last week (24Sep09).