An entertainment network has filed a lawsuit saying they and cable channel MTV, the programme's makers, are in breach of contract - and is asking for unspecified damages.

Threshold.tv says the deal to make the show with MTV deal violates an intellectual property rights agreement between Threshold and the Osbourne's company, Monowise.

Sharon (right) is being treated for colon cancer

Hollywood producer Gary Binkow filed a separate lawsuit against the Osbournes last week, claiming they stole his idea for the show.

The lawsuit, filed in the Los Angeles Superior Court, also names MTV's owner Viacom.

Threshold wants to be declared the owner of the MTV series and all its derivatives.

The complaint alleges a deal made in December 2000 with Threshold gives the network exclusive rights to Ozzy Osbourne's "name, likeness, image, identity, persona, trademarks and right of publicity".

The Osbournes recently signed a £14 million deal for a second series of the reality series which became a surprise hit in the US.

The fly-on-the-wall series about the former Black Sabbath frontman's home life has been pulling audiences of six million in the US and is to be shown in the UK in the autumn.

Sharon Osbourne, 50, is currently being treated for colon cancer.