Controversial Islamic group Hizb ut-Tahrir has been ordered to stop forcibly segregating men and women at its public events after a NSW tribunal found the practice constituted sexual discrimination.

Former NT News journalist Alison Bevege sued the organisation and five of its members for sexual discrimination after she was forced to sit in a designated women's and children's section at a public lecture hosted by the group on October 10, 2014.

Ms Bevege, then a freelance journalist, told the NSW Civil and Administrative Tribunal she attended the lecture, titled "the politics and plots of the American led intervention in Iraq and Syria", with the intention of writing an opinion piece and asking questions of the speakers.

She was "scared" to attend on her own so she arranged to go with a male friend, the tribunal heard.