Actress Emma Watson has revealed how she was leered at, groped and scared by strangers who followed her home as she spoke out against “everyday sexism” in Hollywood.

The Harry Potter star, and UN Women Goodwill ambassador, gave a rare insight into her personal life in an interview to promote the HeForShe campaign for gender equality.

The former Headington School pupil told the latest edition of Esquire magazine, which she guest-edited: "I’ve had my arse slapped as I’ve left a room. I’ve felt scared walking home.

"I’ve had people following me. I don’t talk about these experiences much, because coming from me they’ll sound like a huge deal and I don’t want this to be about me, but most women I know have experienced it and worse. This is, unfortunately, how it is.

"It’s so much more pervasive than we acknowledge. It shouldn’t be an acceptable fact of life that women should be afraid."

Ms Watson joined criticism of the gaps in pay and opportunity for women in Hollywood, saying it is “ridiculous” that only  seven per cent of the top 250 grossing films in 2014 were directed by women.

She said: "Maybe things are opening up a bit for actresses, but certainly as far as female directors are concerned, the numbers are so ridiculous.

"You hear of studio heads being like ‘We can’t have a woman directing an action movie,’ or just sticking to these archaic notions of what a women will and won’t be able to do.”

She accepted that women who speak out face being labelled "feminazis" and “divas” but added: “It’s not going to stop me from trying to do the right thing.

"It doesn’t just affect me. Hollywood is just a small piece of a gigantic puzzle but it’s in the spotlight.

"Whether you are a woman on a tea plantation in Kenya, or a stockbroker on Wall Street, or a Hollywood actress, no one is being paid equally."

The HeForShe campaign aims to change men’s perception of their role in gender equality. Watson said many men have problems describing themselves as "feminists".

Watson has already won over one high-profile recruit, with two-time Oscar winner Tom Hanks signing up to her cause in an interview she conducted for the magazine.

He told her: "We are in the Third Millennium. We have thousands of years of human history under our belts. If we are not continuously moving towards equal rights, equal opportunities and equal freedoms for every member of the human race — not just the half that is male — then we have squandered all we have learned.

"When rules of gender and character dictate what stories are told and by whom, when women are required to be only hot or only nurturing, they no longer are full dimensional humans.

"That’s not art, and it brings less enlightenment to the world."

Watson is currently taking a year off from acting to read and study.

Her next film will be The Circle, a thriller about tech companies due later this year.