Harry Potter author JK Rowling has ran into fresh controversy after tweeting the Manx flag it what appears to be a row about transgender people.

The world’s top-10 bestselling writer posted an image of the Three Legs of Mann with the caption ‘I’m not angry, Julie, just deeply disappointed. Should you decide to reflect, learn and do better, you can start by displaying the thirder flag on all future tweets’ as a response to journalist Julie Bindel.

‘Thirder’ may refer to ‘third gender’ – where people are categorised, either by themselves or by society, as neither a man nor a woman.

Rowling has in recent years become a controversial figure when many of her former fans perceived remarks that she made about transgender people to be transphobic.

Most notably, she has taken issue with people who were assigned male at birth choosing to identify as women after coming out as transgender.

Former Czech Wimbledon star Martina Navratilova was also part of the conversation on Twitter, saying that she wished she could have been at the meeting and lunch which Rowling had initially been tweeting about, which appeared to be a gathering of feminist activists.

The writer’s exchange on Twitter received backlash, with people saying that she was mocking both transgender people, and later, those with PTSD.

And a number of Manx residents replied to her, calling her out on using the flag and seeking to inform her that it was their national flag.

Douglas East MHK Clare Barber also waded into the discussion, tweeting: ‘This year we celebrate our 2nd @isleofpride festival and mark 30 years since the decriminalisation of homosexual acts; we stand firm with all marginalised communities and celebrate our trans community and those with mental illness.

‘Using our flag in this debate is not ok.’