Opera singer and film writer ex-boyfriend in High Court battle over who wrote the script to a Hollywood blockbuster

An opera singer is locked in a High Court battle with her film writer former boyfriend over who wrote the script to a Hollywood blockbuster.

Julia Kogan claims she helped Nicholas Martin write the award-winning 2016 film Florence Foster Jenkins, starring Meryl Streep and Hugh Grant, while the pair were in a loving relationship.

She told the court she deserved a slice of the profits and a credit on the Oscar-nominated film, that took more than £33 million at the box office.

The musical comedy-drama, directed by Stephen Frears, was based on the true-life story of Florence Foster Jenkins, a New York socialite with a notoriously bad singing voice, who nevertheless achieved her ambition to become an opera singer and sold out Carnegie Hall.

The film was London-based Mr Martin's first Hollywood success.

Miss Kogan claimed the script was the product of a "closely intertwined collaboration" with Mr Martin that they began in February 2013.

But Mr Martin insisted that he was the sole author of the acclaimed script, while she was "simply a supportive girlfriend."

Her contribution was mostly "guff" and was nowhere near enough to "promote her into an author," he argued.

Mr Martin, who is in his 50s, left school with no qualifications and worked as a bouncer and a croupier before training as a TV screenwriter.

He wrote episodes of Midsomer Murders and The Bill during a 20-year long television career, before finally breaking into the big time with the Hollywood script.

But Miss Kogan, from west London, who is in her 40s, said he could never have written the story without her help and experience, garnered from her career as an award-winning professional opera singer.

The court heard the couple met in 2011, with Mr Martin later saying he "liked her intelligence and larger than life personality."

She moved into his Tooting flat in February 2012, and the couple's "romantic relationship" lasted three years until they split in October 2014.

During that time, her barrister Simon Malynicz QC said, the script was born out of "two highly literate and creative people exchanging ideas and words freely.”

He told Judge Richard Hacon: "Miss 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.”

She had contributed "comedic dialogue" to "the most memorable scene in the movie" and "terminology that was used hilariously from the opera world," he claimed.

Her concrete input also included "a theme of 'loveliness'" that pervaded the whole film and "some minor characters and minor dramatic events."

"Actual text written by Miss Kogan ended up almost verbatim in the final draft," claimed Mr Malynicz.

Tom Weisselberg QC, for Mr Martin, told the judge Miss Kogan had contributed only "guff," criticism and musical advice to the process of creating the script.

"There is no contemporaneous documentary evidence whatsoever which shows Miss Kogan writing a single line of the screenplay," he said.

"In contrast, there is clear contemporaneous documentary evidence showing Mr Martin to be the sole author of the screenplay.

"As a matter of law, none of these things promote her into an author," he told the court.

Judge Hacon reserved his judgement and will give his ruling at later date.