Girls creator and star Lena Dunham has said “every woman who comes forward deserves to be heard, fully and completely” as she apologised for defending a writer on the show accused of sexual assault.

Dunham had been widely criticised for weighing in on allegations made against Murray Miller by another actress.

A statement from Dunham and the show’s executive producer Jenni Konner had said: “Our insider knowledge of Murray’s situation makes us confident that sadly this accusation is one of the 3% of assault cases that are misreported every year.”

Dunham has now apologised, writing on Twitter: “As feminists, we live and die by our politics, and believing women is the first choice we make every single day when we wake up.

“Therefore I never thought I would issue a statement publically supporting someone accused of sexual assault, but I naively believed it was important to share my perspective on my friend’s situation as it has transpired behind the scenes over the last few months.

“I now understand that it was absolutely the wrong time to come forward with such a statement and I am so sorry.

“We have been given the gift of powerful voices and by speaking out we were putting our thumb on the scale and it was wrong. We regret this decision with every fiber of our being.”

She continued: “Every woman who comes forward deserves to be heard, fully and completely, and our relationship to the accused should not be part of the calculation anyone makes when examining her case.

“Every person and every feminist should be required to hear her.

“Under patriarchy, ‘I believe you’ is essential.

“Until we are all believed, none of us will be believed. We apologize to any women who have been disappointed.”

Matthew Walerstein, a lawyer for Miller, told the Press Association the writer “categorically and vehemently” denies the allegation against him and that Miller’s legal team has “gathered overwhelming evidence directly contradicting these false and offensive claims”.

He added: “Mr Miller looks forward to sharing all evidence and information with any and all authorities seeking the truth in this matter.”