A modern slavery investigation into the Australian fruit industry is underway after accusations of "brainwashed" and "underpaid workers".

Malaysian journalist Saiful Hasam went undercover and says workers are lured over with promises of high income and a place to stay.

Hasam posed as a worker and says he was paid $110 for 24 hours work and lived in a small home with 11 other workers.

Australian correspondent Donna Demaio told Rachel Smalley the inquiry has heard money isn't working its way through the system.

"Citrus Australia saying that actual growers did pay the right amount to the business employing the workers. She claimed the businesses are not passing it on to the actual fruit pickers."

LISTEN ABOVE TO DONNA DEMAIO TALK WITH RACHEL SMALLEY