Julianne Moore was sacked from Oscar-nominated film Can You Ever Forgive Me? because she wanted to wear a fat suit, its star Richard E Grant has claimed.
According to Grant, Moore also wanted to don a false nose to play literary forger Lee Israel - but the film's then director did not approve.
"Nicole Holofcener said 'you're not going to do that'," Grant told an audience in London on Wednesday.
Moore revealed this month she was fired from the film without giving details.
"I think she didn't like what I was doing," she said of Holofcener, who did not end up directing the film.
Moore's departure was previously attributed to unspecified "creative differences". Melissa McCarthy eventually played Israel in the film.
Moore's representatives have been approached for comment.
Speaking at an Advertising Week Europe event in London, Grant said Helena Bonham Carter and Sam Rockwell were also attached to the film before he became involved.
Grant, known for his roles in Withnail and I and Downton Abbey, received an Oscar nomination for his role as Jack Hock, Israel's inebriated accomplice.
Irish actor Chris O'Dowd had been due to play the part opposite Moore, only to find out "at the last minute" the shoot would not be going ahead.
During a free-wheeling talk on Wednesday, Grant also revealed he had received a phone call from Spice Girl Geri Halliwell the previous day.
He did not disclose what they spoke about, but joked he could fill in for Victoria Beckham when the band embark on their reunion tour.
Grant went on to reveal he still had some of the costumes he wore to play Clifford, the group's uptight manager, in 1997 film Spice World.
He also poured scorn on his "snooty" fellow actors who had disparaged him for accepting a role in the Spice Girls' sole film outing.
The actor said his 2014 appearance in TV show Girls had only come about because its creator, Lena Dunham, had been a fan of the film.
"Then Adele sent me tickets to her sold-out concert at the O2 because she knew me from Spice World, so it's a double win," he continued.
The Spice Girls, minus Beckham, will give 13 concerts in the UK and Ireland between 24 May and 15 June.