FIVE Thai women brought to Australia to work in the sex industry were told they had to service up to 750 clients before they could earn their own money, a court has heard.

Four men, Kam Tin Ho, Ho Kam Ho, Chee Fui Hoo and Slamet Edy Rahardjo, are on trial in the Victorian Supreme Court over their alleged role in the scheme.

Crown prosecutor Daniel Gurvich said each of the men had pleaded not guilty to taking part in bringing Thai women to Australia to profit from their willingness to work for minimum rewards in the local sex industry.

The scheme was sophisticated and well planned and the conditions the women were forced to endure were tantamount to slavery, he said.

"They were traded, possessed and used as items of profit, reducing them to the condition of slavery,'' Mr Gurvich told the jury.

He said the women mainly worked at two South Melbourne brothels, were not allowed to go out without company and their passports were taken from them.

The women were told that before they could earn money to keep themselves, they had to service a certain number of clients to pay off a debt, Mr Gurvich said.

Some of the women were told they had to service between 650 and 750 clients.

The women received $5 from the $125 clients paid for their sexual services and another $50 was deducted from the payment towards their debt.

Mr Gurvich said the women sent money they earned back to their families in Thailand.

The trial before Justice Philip Cummins continues.