British director Mike Leigh has scooped two prestigious US awards for Topsy-Turvy, his epic film about the Victorian composers Gilbert and Sullivan.

The film, which depicts a period late in the careers of Sir Arthur Sullivan and WS Gilbert, was named Best Film by the New York Film Critics' Circle and Leigh won Best Director.

The Circle's chairman, Owen Gleiberman of Entertainment Weekly, said: "It takes you inside Victorian London... it''s a one-of-a-kind film."

Topsy-Turvy's actors, led by Jim Broadbent and Allan Corduner, largely improvised, working without benefit of a formal script.

The movie awards season started last week, but no clear favourite for next March's Oscars has emerged.

The Los Angeles Film Critics' Circle named The Insider as the year's best movie, while the National Board of Review plumped for American Beauty.

Acting awards from the New York Film Critics' Circle went to veteran Richard Farnsworth for his quiet depiction of Alvin Straight in the David Lynch film The Straight Story.

Hilary Swank was named Best Actress for her portrayal of a young woman living life in rural Nebraska as a young man in Boys Don't Cry.

Spike Jonze's Being John Malkovich, a quirky comedy that takes place inside the head of the actor, won best first film. It also scooped both supporting actor categories - for Malkovich, who played himself, and for actress Catherine Keener.

Spanish director Pedro Almodovar's All About My Mother, a comedy that has been sweeping critics' honours, won Best Foreign Film.

Best Screenplay went to the high school satire Election, while The Straight Story, a true story of an elderly man who drove a lawn mower from Iowa to Wisconsin to visit his ailing brother, won Best Cinematography.

South Park honoured

The critics also chose a best animated film for the first time in the 65-year history of the awards, selecting South Park: Bigger, Longer and Uncut over big budget rivals such as Disney's Toy Story 2 and Pokemon: The First Movie.

German director Wim Wenders' The Buena Vista Social Club, about the Cuban musical group of the same name, was named Best Documentary.

The New York Film Critics' Circle will present its awards on 9 January in New York. The group was founded in 1935, and is made up of critics from major New York-based newspapers and magazines.