Katy Perry's Twitter followers get sneak peek at concert movie

Katy Perry is offering her Twitter followers the chance to catch a sneak peek of her new 3D concert movie Part Of Me - three days before the film hits cinemas.

Paramount bosses are planning to screen the movie in 100 cinemas across the U.S. on 2 July.

Movie executives and Twitter.com bosses have joined forces to create a special hashtag that will direct fans to a site where they can buy tickets for the advance showings.

Perry has 22 million Twitter followers.