Polanski, 76, reportedly raped a 13-year-old girl in 1977, pleaded guilty to the charge and then left the United States before the case was heard by a court. 

Polanski was accused of raping the girl while photographing her during a modelling session. She said he gave her champagne and part of a quaalude pill at Jack Nicholson's house in California, while the actor was away.

But legal experts are saying the United State's sudden desire to extradite Polanski, the director of films including Chinatown, The Pianist and 30 others, is a waste of resources. 

"[It] really doesn't make any sense unless you're talking about a child predator" with repeated predatory behaviours, UCLA law professor Peter Arnella told ABCnews.com, the US site. 

He said legal experts are trying to watch the case and "figure out why a three-decade-old statutory rape conviction was worth an international manhunt". 

He questioned why Polanski had suddenly become such an object of interest for the Los Angeles district attorney's office, at a time as well when the state of California is particularly cash-strapped. 

Polanski has long sought to have the statutory rape charges against him dropped, but has refused to return to the US to have the trial heard.