The semi-autobiographical picture about teenage love and immigrant life in the Lower East Side won the main Flame of Deauville prize at the event in Normandy.

It follows young Victor, who is raised by his grandmother, a migrant from the Dominican Republic. He develops a crush on the overweight, unpopular girl upstairs - which threatens to ruin his street credibility.

The film is about growing up in New York

The Deauville festival specialises in US films, and Long Way Home reflected the general mood of angst and introspection which surrounded the event this year.

Long Way Home was Sollett's first feature film, and he used amateur performers to explore themes of identity and growing up, as well as the challenges facing immigrants in the US.

Robin Williams' unusual performance in Mark Romanek's One Hour Photo, where he plays an unbalanced and obsessed photo developer, helped the film win the audience Prix du Public award.

The jury prize was shared by One Hour Photo and Michael Cuesta's Long Island Expressway (LIE), about a teenage boy's complex relationship with a much older man.

Robin Williams helped One Hour Photo win honours

A separate jury prize was handed to Patricia Clarkson for her portrayal of a suburban mother going through a painful divorce in The Safety of Objects.

Best short film went to Crossing, by Jeremy Passmore.

The emphasis at Deauville is on independent movies, and this year's main jury was headed up by Pierre Lescure, the former boss of cable network Canal Plus.

He hit the headlines in April for suspending the service's regular programmes after he was fired, to mount an attack on the management of its parent company Vivendi Universal.

The festival is also used to show off Hollywood's latest blockbusters. Films shown out of competition included spy thrillers XXX and The Bourne Identity, and gangster epic Road to Perdition.