As reported in the Herald on Saturday, pickers accused the Bundaberg labour hire contractor Mehmet ''Max'' Tosun of the abuses after he recruited them from East Bundy Backpackers, the hostel he runs with his wife, Calie.

Their local paper, the News Mail, quotes a former employee, Peter Pader, saying he witnessed Mr Tosun slap workers, refuse them water and force drivers to operate unroadworthy buses.

"You think he treats foreigners bad,'' Mr Pader said. ''Then you should see how he treats locals. I've also seen him slap two guys. They were either Indian or Bangladeshi."

The couple have refused to respond to questions but SP Exports, a company that used Mr Tosun's workers, has terminated his contract after finding substance to pickers' allegations.

The Fair Work Ombudsman, a federal agency, and Queensland's Workplace Rights Ombudsman, Don Brown, have launched separate investigations.

After the Herald revealed workers were paid as little as $9.60 for a day's work - apparently based on $1.80 a bucket of tomatoes - the federal ombudsman has warned pickers to: keep their own records of wages and hours worked; be aware of minimum entitlements which, even on piece rates, must amount to at least $14.31 an hour, plus a loading for casuals; insist upon a payslip; know the business name and Australian Business Number of their employer; and ask for job offers and terms of employment in writing.

The Tosuns told backpackers they could only get work if they stayed at their hostel. When Mr Tosun sacked pickers, they were told to leave the hostel, with no refund for nights paid in advance.

Under the Fair Work Act, an employer ''cannot directly or indirectly require an employee to spend any part of wages payable to them if the requirement is unreasonable'', the federal ombudsman's spokesman said.

The state ombudsman, Don Brown, will have an investigator in the town this week.

A hostel owner, John Walker, rejects Mr Brown's argument that the hostels are, in effect, private employment agencies. Mr Walker says he takes no commission from farms.

Mr Brown says hostels have an obligation to warn pickers of their rights and growers cannot blame labour hire contractors.

''Anyone with a functioning brain, and I refer here to the growers, should know exactly what those people are being paid and by whom. The fact they feign or choose ignorance doesn't get them off the hook.''