Scooby-Doo will be followed by a sequel after the movie broke box office records for a June opening.

After its mixture of comic camp and kitsch proved a hit with a modern audience, Warner Bros are anxious to repeat the formula.

Moves are already being made to take a sequel to the live action version Hanna-Barbera cartoon into production, following a $54.2m (�36.2m) opening weekend.

Warner announced that Freddie Prinze Jr, Sarah Michelle Gellar, Matthew Lillard and Linda Cardellini will come back as Fred, Daphne, Shaggy and Velma, who solve mysteries with the help of their Great Dane, Scooby-Doo.

Raja Gosnell, who directed the first movie, will return, as will screenwriter James Gunn.

Production is expected to begin early next year in Los Angeles, with release scheduled for 2004.

Similar mysteries

Lorenzo di Bonaventura, Warners' president of worldwide production, said: "Our cast and filmmakers really brought this animated series to life on the big screen.

"We feel certain that we've got another great Scooby-Doo story to tell in movie theatres two years from now."

The cartoon told the story of four young sleuths who solved a series of very similar mysteries set in haunted theme parks and hotels with the aid of their dog.

Its 1960s feel and apparent drug references have made it a cult favourite with adults as well as children.

Fans have taken to the movie, accepting that it has captured the spirit of the original cartoon.

Its healthy opening weekend gave the movie the accolade of being the biggest June opener ever, beating the three-year record set by the second Austin Powers movie.