Rebel Wilson vows to tell all during defamation court case

Rebel Wilson poses for photographers upon arrival at the Elle Style Awards in London in 2015. Photo / AP

Hollywood movie star Rebel Wilson has rapped a hallucinated Oscar acceptance speech in court.

In the most showbiz of trials to come before Australia's Victorian Supreme Court in years, Wilson took the stand as the first witness in her case against Bauer Media, the Herald Sun reported.

Wilson is suing the publisher of Woman's Day and Australian Women's Weekly over a series of articles published in 2015 she says destroyed her career.

Minutes into giving evidence on Tuesday morning the expat Aussie actor wiped away tears, telling the court it was going to be an emotional day.

"I try to be an upbeat positive person most of the time.

"When I hear the story again ... I can't help it. The emotions just come up," she said.

She claims the articles at the centre of the trial alleged Wilson had lied about her age, name, and background, which cost her prestigious roles in hit movies.

Wilson told the court today her age was 37, and confirmed she was born Melanie Bownds, which she later legally changed to Rebel Wilson.

"The name Rebel comes from ... a little girl ... that sang at my parent's wedding," she said.

"My mum, who is a teacher, thought this girl was a little angel. My mum had always wanted to call her first girl Rebel."

Wilson said her parents argued about the name, with her dad preferring the more "normal" name, Melanie.

"My dad won out, and Melanie was put on the birth certificate. I was always aware Rebel was supposed to be my name and Rebel was my nickname."

Wilson said she changed her surname after her parents separated when she was a teenager.

She hit out at the articles at the centre of the lawsuit, saying they killed her career.

"These articles were a deliberate malicious take-down of me. I don't know what other words you would use apart from nasty to describe these articles," she said.

"They don't know me, they haven't lived my life. I have. I know what's true, and I'm happy to tell my story today."

Wilson's evidence is expected to take all day.

The jury was shown an entire episode of the ABC's Julia Zemiro's Home Delivery, featuring Wilson.

In it she was critical of the Australian media she said unfairly attacked Australian celebrities.

Wilson rapped an Oscar acceptance speech she said she contracted while doing charity work in South Africa during a gap year after finishing high school.

Her immediate family and actor Hugh Sheridan are all expected to give evidence during the three week trial.

The hearing, before Justice John Dixon, continues.

- This story appeared on news.com.au