Opera star battles her ex for share of £33 million blockbuster Florence Foster Jenkins

An opera singer who claims she helped to write a Hollywood hit starring Meryl Streep and Hugh Grant is locked in a court battle with her ex-boyfriend over credit for the script.

Julia Kogan says she was integral to 2016’s Florence Foster Jenkins, working with Nicholas Martin as he wrote the screenplay.

But she told the High Court that Mr Martin took full credit for the project as it was bought up by a Hollywood studio. It took more than £33 million ($44 million) at the box office.

In the film, Streep plays Florence Foster Jenkins, a New York socialite in the Forties with a notoriously bad singing voice who achieves her dream of becoming an opera singer and sells out Carnegie Hall. Grant plays her husband.

Ms Kogan wants a slice of the profits from the Oscar-nominated film and a credit.

Her barrister Simon Malynicz QC said the script was formed during their relationship as “two highly literate and creative people exchanged ideas and words freely”.

He said the pair enjoyed a “closely intertwined collaboration”.

Tom Weisselberg QC, for Mr Martin, said Ms Kogan had contributed only “guff” to the scriptwriting process. He said: “She acted as a proof reader, a critic, a supportive lover and a sounding board. As a matter of law, none of these things promote her into an author.”

The court has heard Mr Martin, in his fifties and from Tooting, left school with no qualifications before training as a TV scriptwriter. He wrote episodes of Midsomer Murders and The Bill.

In 2011 he started dating Ms Kogan, from Fulham and in her forties. By October 2014 they had broken up. The film was released in August last year.

Ms Kogan “always said in public that it was Mr Martin’s project because her expectation was that, if she confronted him with what was happening, then she would lose him,” Mr Malynicz said.

“Florence Foster Jenkins is fundamentally about an opera singer, opera singing and rehearsing and the world of opera in the Forties, milieux of which Mr Martin had no experience, knew nothing and which had never formed the subject of any previous work by him.

“By contrast Ms Kogan was and is a modestly successful professional opera singer, with appearances at Carnegie Hall among other famous venues, where a key part of the action takes place in the film.

She brought an insider’s view of how opera singers perform and rehearse, as well as a detailed knowledge of opera music which forms a critical part of the film.”

He said “text written by Ms Kogan ended up almost verbatim in the final draft” and claimed director Stephen Frears had acknowledged her contribution.

But Mr Weisselberg said: “There is no contemporaneous documentary evidence whatsoever which shows Ms Kogan writing a single line.”

Ms Kogan is seeking an injunction against three production firms to prevent them publishing the script without her being jointly credited.

The companies are backing Mr Martin, pointing to an email she had sent him about the film, saying: “This is totally your baby.” Judge Richard Hacon has reserved judgment to a later date.