"I didn't leave that movie, I was fired," the actress told host Andy Cohen when asked about the film.
"I think she (director Nicole Holofcener) didn't like what I was doing. We just had been rehearsing and doing pre-production and stuff and her idea of where the character was was different than where my idea of where the character was, so she fired me."
Julianne Moore was originally cast as Lee Israel. Photo / Getty Images
Moore confessed in the interview that she still hadn't seen the film because "it's still kind of painful".
Richard E. Grant was asked about Moore's sacking at an event in London and he spilled the beans about why the actress was really given the boot.
"Julianne Moore wanted to wear a fat suit and a false nose to play Lee Israel and Nicole Holofcener said, 'You're not going to do that'," Grant told Empire's editor-in-chief Terri White in London.
Melissa McCarthy with Richard E. Grant in Can You Ever Forgive Me? Photo / Supplied
Both Grant and McCarthy were nominated for Oscars for their roles in Can You Ever Forgive Me? which news.com.au's Wenlei Ma gave four stars.
"McCarthy has further proven her versatility as an actor," Ma wrote in her review. "As Lee, she captures this complicated woman who knows she's talented but is eternally frustrated at the world — driving her fears, insecurities and a penchant for pushing people away.
"It should also be noted that McCarthy isn't afraid to make Lee unlikeable, leaning into the selfishness and antagonism of the character, but still makes her empathetic."