Daniel Radcliffe is ''deeply sorry'' to anyone who feels the 'Harry Potter' books have been ''tarnished or diminished'' following a controversial comment by J.K. Rowling, for which she was accused of being transphobic.

The 30-year-old star - who played the titular wizard in the movie adaptations of the novels - insisted ''transgender women are women'' and apologised for the ''pain'' the 54-year-old author's comments may have caused people, after she reacted to an article titled 'Opinion: Creating a more equal post COVID-19 world for people who menstruate'.

Her tweet read: '''People who menstruate.' I'm sure there used to be a word for those people. Someone help me out. Wumben? Wimpund? Woomud? (sic)''

In a statement through the LGBTQ suicide prevention charity The Trevor Project, Daniel said in response: ''Transgender women are women. Any statement to the contrary erases the identity and dignity of transgender people and goes against all advice given by professional health care associations who have far more expertise on this subject matter than either Jo or I. According to The Trevor Project, 78 per cent of transgender and nonbinary youth reported being the subject of discrimination due to their gender identity. It's clear that we need to do more to support transgender and nonbinary people, not invalidate their identities, and not cause further harm.

''To all the people who now feel that their experience of the books has been tarnished or diminished, I am deeply sorry for the pain these comments have caused you. I really hope that you don't entirely lose what was valuable in these stories to you. If these books taught you that love is the strongest force in the universe, capable of overcoming anything; if they taught you that strength is found in diversity, and that dogmatic ideas of pureness lead to the oppression of vulnerable groups; if you believe that a particular character is trans, nonbinary, or gender fluid, or that they are gay or bisexual; if you found anything in these stories that resonated with you and helped you at any time in your life - then that is between you and the book that you read, and it is sacred. And in my opinion nobody can touch that. It means to you what it means to you and I hope that these comments will not taint that too much.

''Love always, Dan (sic)''

J.K. subsequently defended her comments on the social media platform, after being inundated with criticism, by strongly denying transphobic claims and insisting she loves the trans community.

She wrote: ''If sex isn't real, there's no same-sex attraction. If sex isn't real, the lived reality of women globally is erased. I know and love trans people, but erasing the concept of sex removes the ability of many to meaningfully discuss their lives. It isn't hate to speak the truth.

''I respect every trans person's right to live any way that feels authentic and comfortable to them. I'd march with you if you were discriminated against on the basis of being trans. (sic)''

J.K. also claimed she has researched the trans community over the ''last three years''.

The writer said: ''I've spent much of the last three years reading books, blogs and scientific papers by trans people, medics and gender specialists. I know exactly what the distinction is. Never assume that because someone thinks differently, they have no knowledge. (sic)''