Katy Perry's 'Part of Me' film has performed somewhat disappointingly at the US box office.

The Los Angeles Times reports that the 3D film, which was released on July 5, took in $7.2 million on its opening weekend.

It's a far cry however from the likes of blockbuster 'The Amazing Spider-Man', which managed to gross $65 million last weekend and $140 million in its first six days of release.

NME meanwhile reports that Perry's 'Part of Me', which documents her life, has performed poorly compared to other music related films released in recent years.

Justin Bieber's 2011 flick 'Never Say Never' took in $29 million during its first weekend, whilst 'Hannah Montana: Best of Both Worlds Concert Tour' managed to shift $31.1m in its opening weekend back in 2008.