Idris Elba has rejected allegations by female writers that they suffered "intimidation and disrespect" after being removed from one of his plays.
The 46-year-old Luther star also described an "accusation of plagiarism and discrimination" as "frustrating".
Sarah Henley and Tori Allen-Martin said they worked on Tree, a musical theatre production about life in South Africa after Nelson Mandela, for four years before being "pushed off the project by far more powerful people".
In a message on Twitter, Elba said the show - credited to Elba and theatre director Kwame Kwei-Armah - had been inspired by a visit to South Africa in 2013, shortly after the funeral of his Sierra Leonean father.
He said the two women had voluntarily left the project, which stars Sinead Cusack and Alfred Enoch, premieres at the Manchester International Festival (MIF) later this month, and that this was "not uncommon in the creative process".
He said: "I approached Kwame - alongside MIF - as a collaborator and theatre partner, with Tori and Sarah to write.
"I thought this could be an incredible opportunity for Tori and Sarah to collaborate with MIF and Young Vic and hone their craft further, and we wanted to provide the support needed; they were excited by the project.
"As new ambitions started to be proposed as the jumping off point for development, Tori and Sarah decided they didn't want to pursue (them) and declined to work any further on the project.
"This is not uncommon in the creative process," he added.
"We wanted to offer an opportunity to support these new writers while creating a piece of work of scale and to a director's vision.
"The outcome is an accusation of plagiarism and discrimination. However frustrating this has been for all, we will continue to offer opportunities and to support the next generation of writers and talent."
In a blog post titled Tree. A Story Of Gender And Power In Theatre, Henley and Allen-Martin claimed they were threatened with legal action if they spoke out publicly.
Producers responded with a statement, saying they were "deeply saddened" to read the writers' allegations.
MIF, London's Young Vic theatre and Elba's production company, Green Door Pictures, accepted that the women were involved in "exploring ideas" for the project, but they "did not feel their proposed direction was artistically viable".
John McGrath, artistic director and chief executive of MIF, said Kwei-Armah was invited on to the project by Elba and his involvement "has been characterised by the integrity and creativity for which he is widely known".
The script is "entirely his creation", McGrath added.
Allen-Martin and Henley's blog post alleges they became "completely disposable" after working on Tree for four years, "because we're not famous or important enough".
They acknowledge the project will have changed over its development, but said: "We put four years of work into that project, and the majority of those involved read our script, our proposal documents, our premise, and our synopsis - there is no way it's a 'different project', no matter how much it's changed."
"We were expected to shut up, lie down, and take it," they added.