SARAH FERGUSON, PRESENTER: They're supposed to be here on a working holiday, but for thousands of young Taiwanese, their trip to Australia is anything but. The young Asian workers say they're being ripped off, harassed and forced to work unreasonable hours. They're recruited by labour hire agencies who send them to work in some cases for major Australian companies. This report from Matt Peacock.

MATT PEACOCK, REPORTER: 5 am at the Scone meatworks in the NSW Upper Hunter Valley and the morning shift is reporting for work. The vast majority are hundreds of young Taiwanese backpackers, not locals. They're in the country on 417 visas for up to two years' working holiday. The meatworkers' union says it's anything but a holiday.

GRANT COURTNEY, SEC., MEATWORKERS' UNION, NEWCASTLE BRANCH: We're talking about excessive hours of work, we're talking about gross underpayments, we're talking about mistreatment, we're talking about allegations of sexual harassment by some of the contract bosses.

IAN TAM, MEATWORKERS' UNION INTERNATIONAL OFFICER: If you say something wrong, say something not good for the company, you have lost your jobs.

MATT PEACOCK: Robert Baker's a local who's worked as a slaughterman for 20 years. When he returned from interstate to work here in Scone, he was shocked.

Hunter Valley Meats, but not very local?

ROBERT BAKER, SLAUGHTERMAN: No, not very local at all. All internationals - 90 per cent, anyway, as was seen when I first walked in. Pretty astonishing as to the workers that they've got on site.

MATT PEACOCK: After working for three months before quitting over safety concerns, Robert Baker now worries about the Taiwanese friends that he's made.

ROBERT BAKER: They were getting mistreated and underpaid. Just like anyone: if you do the work, you should be paid for it

GRANT COURTNEY: Not even half the minimum Australian wage is being paid to a lot of these international workers and that's simply not fair and it's not just and I don't think any Australian worker would cop it.

MATT PEACOCK: Meatworkers' union secretary Grant Courtney's been investigating the plight of the international workers for the past two years.

GRANT COURTNEY: We estimate that there's over 10,000 temporary international workers working in - from backpacker visas in our industry.

MATT PEACOCK: Ian Tam, recently recruited by the union as a Taiwanese liaison officer, has collected 75 signatures accusing a Scone abattoir supervisor of sexual harassment.

IAN TAM: For example, some part, you know, ladies, you cannot touch them, for example the chest, the ass, you cannot touch it.

MATT PEACOCK: The petition says, "He touches body parts like hands, shoulders, loins, face and really any location. It makes us feel very uncomfortable and disgusting, as he is our supervisor and agent. We are afraid to say anything for fear of losing our job."

IAN TAM: That supervisor try to keep doing that every day and the ladies keep saying, "No". Nothing - nothing change. Still doing that.

MATT PEACOCK: Scone meatworks is owned by the smallgoods manufacturer Primo. We sought a response from the general manager, Peter Allen.

PETER ALLEN, GM, HUNTER VALLEY MEATS: Put all the gear back in your car. You're not official visitors on the site, so.

MATT PEACOCK: I'll put this back?

PETER ALLEN: Put it all back. Go and jump in your car. We'll talk as we go back out there.

MATT PEACOCK: But Mr Allen refused to answer our questions, even though the union says it put the sexual harassment allegations to the company late last year.

PETER ALLEN: This site's owned by Primo, so Primo is a smallgoods processor...

MATT PEACOCK: Sure.

PETER ALLEN: so everything - even though I'm the general manager of the site, it will go through...

MATT PEACOCK: Go through head office.

PETER ALLEN: our senior people.

MATT PEACOCK: OK.

PETER ALLEN: So you'll do nothing here. You can pack everything away and then leave the site.

MATT PEACOCK: The union claims Primo uses specialised labour hire companies to employ the Asian backpackers.

It's here in the Sydney suburb of Auburn that Scottwell International recruited many of the young Taiwanese through a variety of labour hire companies. Scottwell on its website says its principal business is the recruitment of Chinese, Taiwanese, Japanese and Korean employees to work in abattoirs and slaughterhouses across Australia, now at 19 different abattoirs across three states and employing more than 1,100 people.

Hi, I'm Matt Peacock from ABC television. Is Scott Shi here? Mr Scott Shi?

The director of Scottwell, Scott Zunin (phonetic spelling) Shi, wasn't available to speak with us.

Mr Shi never returned our call.

But a few weeks ago, Ian Tam went undercover at Scottwell. He says backpackers are being encouraged not to pay tax by using ABN numbers.

IAN TAM: I investigate this agency. I am just pretending I'm one of them, OK, like a backpackers looking for jobs. They would give you a form to fill in. Quick, very quick interview. OK, will ask you, "Can you work now?" OK, they will send you to a place, no matter in Scone or in Queensland or in Victoria, tomorrow you will start work, very soon. OK, they would give you lots of forms to fill in, including ABN forms. OK, then you ask them, "How about tax file number?" they will just tell you, "OK, do not worry about that. You don't need to pay tax. You can earn more money using ABN." If not sign those document, you cannot get the job.

GRANT COURTNEY: I'm a meatworker and I am livid, absolutely livid with this issue. Like, all of our workers are willing and able to pay tax. Temporary international workers are usually very well-educated workers and they pay tax in their own country.

MATT PEACOCK: Even the Taiwanese Government's Joseph Chow in Sydney is worried.

JOSEPH CHOW, TAIPEI ECONOMIC AND CULTURAL OFFICE: Since 2004 there are about 100,000 young Taiwanese people have been in Australia doing - working holiday visa scheme and just about last year there are about over 35,000 young Chinese people here. So, we are very concerned about their safety. We are very concerned about their fairness to be treated.

MATT PEACOCK: Primo is the country's largest meat manufacturer, founded and still run by the wealthy Lederer family. Its CEO, multi-millionaire Paul Lederer, leads a consortium which it's believed recently bought the Wanderers, Western Sydney's soccer club.

Back at Primo's Sydney headquarters here, no-one was prepared to do a television issue either, although the company eventually did issue a statement.

STATEMENT FROM PRIMO AUSTRALIA (male voiceover): "Any report on harassment is taken seriously. We have recently received a complaint ... and have now addressed this with the individual's employer, the labour hire agency. Allegations of workers being encouraged for to pay tax are untrue. We do not employ anyone under a 417 visa. We do engage the services of labour hire agencies. It may be more appropriate to address ... them."

MATT PEACOCK: But what about the employees of the labour hire companies, not Primo's direct employees? Are they paid enough? Are they paying enough tax? And do they have to pay their medical expenses? "We don't know," says Primo, "you'd have to ask the labour hire company."

GRANT COURTNEY: There needs to be, clearly, changes so temporary international workers cannot access an ABN within 65 seconds of getting into the country. Like, all ABN - or all 417 visa workers should be directly employed by these companies, not through labour agencies. That will fix the problem.

ROBERT BAKER: To have these guys not even pay tax and take our jobs, that's bad. Like, how are they allowing it to happen? It shouldn't be allowed to happen.

SARAH FERGUSON: Matt Peacock reporting.