This Is It, the movie which follows Michael Jackson's final days, has premiered simultaneously in 19 cities around the world.

The documentary attracted a star-studded guestlist in Los Angeles, where Jennifer Lopez and Will Smith walked a Jackson-inspired red carpet.

The late singer's brothers Jermaine, Marlon, Tito and Randy also attended the event.

Directed by choreographer Kenny Ortega, This Is It has been created from over 100 hours of behind-the-scenes footage of Jackson as he rehearsed for his planned London comeback shows.

They were due to begin just two weeks after his sudden death in Los Angeles on June 25.

Speaking at the Los Angeles premiere, Jermaine Jackson, who had yet to see the film, told MTV he was “very, very healthy” in the build up to the concerts.

Jennifer Love Hewitt, Katy Perry and Paris Hilton were also among guests on the red carpet.

In London, the film attracted a less star-studded guestlist but hundreds of fans still descended on Leicester Square for the premiere.

Many were dressed in the late singer's stage outfits and performed his dance moves for the assembled media.

This Is It is now on general release for a limited two week period.

Michael Jackson's brothers (left to right): Jermaine, Randy, Tito and Marlon

(by Jason Gregory)