The day of emotional testimony also revealed the lengths celebrity-obsessed magazines go to to sell copies - and how much they're prepared to pay for the most salacious stories.

The actor is suing publisher Bauer Media for defamation over a series of articles published in May 2015 that she claims suggested she was a serial liar who had fabricated her life story.

She said the stories resulted in her getting sacked from Kung Fu Panda 3, where she was to provide the voice of a female panda love interest.

She also developed a large stress-sore on her face meaning several scenes she filmed for How to Be Single had to be cut.

"[I've worked] 17 years, every day, to get to this point," a sobbing Ms Wilson told the court.

"I'm sorry, it's hard to talk, just when I think about every single day since I was an adult working for something, and then this group of people who I don't know who just want to rip me to shreds with information they know is false and they know they shouldn't print.

"And to this day they haven't apologised."

Justice John Dixon offered Ms Wilson a break to compose herself. But she said she would power through - as long as everyone could understand her testimony through the tears.

Mid-testimony, Ms Wilson pointed at Bauer Media's senior lawyer, Georgina Schoff, QC, and said she had discovered Ms Schoff had leaked confidential information about her finances.

The recipient of the information, Ms Wilson claimed, was Ms Schoff's husband.

After an awkward pause, the trial continued.

Ms Wilson also revealed she is a member of Disneyland's Club 33, an invite-only secretive club at Disneyland for celebrities and other high-net-worth individuals.

The club reportedly has a $50,000-plus initiation fee plus $15,000 in annual dues.

The third day of Wilson's defamation trial - expected to run the Supreme Court of Victoria for three weeks - focussed on life behind the scenes at celebrity magazines, where journalists and editors make low-ball cash-offers to get anonymous sources to spill dirt on stars.

Actress Rebel Wilson told the court she had worked '17 years, every day, to get to this point'. Photo: Mal Fairclough

In 2012 a comment was left on Woman's Day's Facebook page, claiming to be from a former schoolmate who had dirt to dish on Ms Wilson. "What a lier [sic] she has become," the comment said.

"OMG oh my god I LOVE this xxx," wrote one magazine employee when the comment was circulated around the office, according to emails tendered by Wilson's legal team.

???I read your comment on the Womans Day site and would LOVE to know more!'
Shari Nementzik, TV Editor, Womans Day

Journalist Shari Nementzik??? negotiated with the source via email: what information did she have, did she have any photos?

"I cannot believe she's a fake, that's awful ... [the story] would never ruin her career, but possibly just expose the real her," Ms Nementzik allegedly emailed.

Ms Nementzik initially offered between $2000 and $8000 for the story and childhood photos - although that offer dropped to only $500 when she discovered what the source had.

???If I am going to do this I am looking for maximum payment, so I won't accept that offer ...'
Email from unidentified source of the story to Womans Day

"She's suggesting if she had a picture of me with a crack pipe she'd give her $8000," Ms Wilson joked when the email was read to court.

The source - who Ms Wilson believes is an obsessed and jealous former classmate - told the magazine Ms Wilson was lying about her name (Melanie), age (33), parents' occupation (accountants, not dog trainers), awards and malaria diagnosis.

Ms Wilson said she was baffled by the claims, all which she said were false and easily disproved with a quick internet search.

Most odd, she said, was a claim she was lying about winning a "best up-and-coming actress under 30 award".

"To my knowledge there is no such award," Ms Wilson told the court.

She said she never revealed her age after moving to Hollywood - but never lied about it either.

Her first name had been legally changed from Melanie to Rebel, she said, and she had photographic evidence of her malaria diagnosis and her parents' dog-training days.

Ms Nementzik did do some research - and discovered the source's claims may not have stacked up, according to emails read out in court.

"We have come into some problems with the story," she wrote to her source.

"We have been doing some research and there are a lot of articles that put her age at 33, and somewhere she says her real name is Melanie. If she has not been lying as such it will be hard to do the story".

After spending a year negotiating with the source, in 2013 Ms Nementzik emailed to say the magazine had legal advice not to publish the story.

"If I was Bauer Media I would have sacked this journalist," Ms Wilson said.

"Not only did she know all this information was fake but she'd taken it to lawyers who said not to publish it."

But then, in 2015, the story was resubmitted for publication, according to emails tendered in court. It would eventually be published in May 2015, around the time the movie Pitch Perfect 2, starring Ms Wilson was released.

Before it was published Fiona Connolly, editor in chief of Woman's Day, emailed Ms Nementzik, worrying "about legals as we're calling her a liar based on a woman who won't go public".

???Also worried about legals as we're calling her a liar based on a woman who won't go public.'
Fiona Connolly, Editor-in-Chief, Womans Day

A later draft was edited to "tone down the woman with the axe to grind", another editor emailed.

The court has heard Bauer will argue that no one would have thought less of Ms Wilson because of the articles, and the articles were largely true

Bauer Media's lawyers are expected to get their chance to cross-examine Ms Wilson later this week.