Several filmmakers screening at this week's Cannes film festival signed a petition released on Tuesday in support of Roman Polanski.
Among the signatories are Jean-Luc Godard, Agnes Varda, Bertrand Tavernier and Olivier Assayas as well as Chile's Patricio Guzman and Romanian Cristi Puiu.
The petition urged the Swiss authorities to take action to help Polanski, saying "The US request for extradition is based on a lie."
A Los Angeles judge on Monday dismissed a request by Polanski's lawyers to unseal records they claimed would prove that attempts to extradite the director were based on incomplete information.
Polanski attorney Chad Hummel had argued it was necessary to release transcripts of closed-door testimony given earlier this year by Roger Gunson, a retired prosecutor who handled the filmmaker's 1970s child sex case.
Hummel claimed in filings last week the testimony would show authorities in Switzerland - where Polanski is under house arrest and facing extradition to the United States - that US prosecutors had withheld information in the case.
Earlier this month Polanski broke his silence on the case, saying in a 900-word statement that US authorities wanted his head "on a platter."
Polanski insisted he had served the time agreed and that claims to the contrary in the extradition warrant were false. The testimony by Gunson supported his version of events, Polanski added in the statement.
However Espinoza rejected the request, stating authorities in Switzerland "have the information they need," to make a decision on Polanski's extradition.
Polanski is alleged to have given 13-year-old Samantha Geimer champagne and drugs during a 1977 photo shoot at the Hollywood Hills home of actor friend Jack Nicholson before having sex with her despite her protests.