Footage has emerged appearing to show a woman being forced out of the female bathrooms in a US coffee shop by police who thought she was a man.

The unidentified woman repeatedly tells police she is female, as her friends jump to her defence, while several officers force her from the public restroom.

The policeman who removes the woman from the bathroom asked her: "You got it? You got no ID, get out," referring to the woman as 'Sir' as she forces her out of the public restroom, despite her friends and other women in the bathroom insisting the woman is female.

The film has been viewed more than 3 million times on Facebook after it was shared by activist Tamara McDaniel, who wrote: "Lesbian harassed and forced to leave a public restroom because the police insist she's a man. Is this what "Make America Great Again" means? This makes me very sad and I want no part of this irrational fear.

"I mean, you can't think of a 1000 ways these laws will be used as an excuse to harass, humiliate, and arrest people?"

The apparent confrontation comes just weeks after clashes between different groups of demonstrators protesting over North Carolina's controversial 'bathroom bill', which has been criticised for discriminating against transgender people and limiting rights for LGBT people.

High-profile politicians have waded into the debate, with Republican presidential hopeful Ted Cruz openly supporting banning transgender people from using the bathroom of the gender they identify with, as opposed to the gender they were prescribed at birth.

He said the bill was about protecting children, stating: "It doesn't make sense for grown adult men, strangers, to be alone in a restroom with a little girl."

His comments have been widely criticised by the LGBT community, while Democrat hopefuls Bernie Sanders and Hillary Clinton have both spoken out in favour of LGBT rights and against the controversial bill.