Sam Smith
Sopher alleges her lyrics were featured in songs featuring Sam Smith and Eliza Doolittle.

An unknown songwriter is suing pop stars Eliza Doolittle and Sam Smith after claiming she wrote the lyrics to their hit songs.

Katie Farrah Sopher alleges that her songbook was stolen by her 'violent' ex-boyfriend Sean Sawyers, who then sold her work to contacts in the music industry, The Mail On Sunday reports.

Sopher is claiming more than £200,000 in damages for four songs which went onto be chart hits.

Three of the songs are from singing duo Disclosure: Latch, which reached number 11 in the charts and featured Smith on vocals; the number two hit White Noise; and You and Me, which featured Doolittle.

Sopher is also seeking damages from dance duo AlunaGeorge, both for their contribution to White Noise and because she claims she wrote the lyrics to their top 20 success Attracting Flies.

She claims the lyrics of all four songs described her abusive five-year relationship with her former partner, including references to domestic violence leaving her 'black and blue' in 2013's White Noise.

In her testimony, she alleges Sawyers "attempted to control [Sopher], was jealous and possessive and ... believed she was cheating on him, which made him violent and reluctant to allow [her] to speak to other men."

Sawyers denies all the allegations against him. In his defence filed with the High Court, Sawyers states: "I am denying all the allegations... There is zero truth to the claims made against me. I never saw the book the claimant mentions... [so] I could not have committed the alleged damages, theft, copyright infringement."

The musicians involved have not responded to requests for comment.