Two brothers jailed for their roles in enslaving Thai women to work in Melbourne's sex industry have been denied leave to appeal in the High Court.
Lawyers for Kam Tin Ho and Ho Kam Ho argued on Friday that the jury which convicted them of possessing slaves had not been briefed adequately on the distinction between slavery and "exploitative employment" by the trial judge.
The men were jailed in 2009 over their treatment of six women who had entered Australia from Thailand on tourist or business visas in 2003 and 2004.
The court heard Kam, who is serving a sentence of 14 and a half years, was the operation's ringleader, while Ho, who was jailed for 10 years, ferried the women between work and home and escorted them on shopping trips.
The women were told they had to pay "contract debts" of up to $90,000 each to secure their trip to Australia and the right to earn money to help their families back home, the court heard.
This involved servicing up to 750 clients, which each did by working six days a week over about four months. During this time they received $5 from each $125 payment, with $50 deducted from the debt.
Only once their debt was fully repaid could the women keep $50 from each job, but even then they were strictly controlled and unable to go outside unsupervised, the court heard.
Christopher Boyce, for Ho Kam Ho, said Supreme Court Justice Lex Lasry had "left the jury at large" and forced them to make a value judgment on whether the women were slaves or poorly-treated employees.
High Court Justices William Gummow and Susan Crennan denied special leave to appeal, backing a Court of Appeal judgment which found Justice Lasry had been clear and had not erred.
"He says exactly what you're implying he didn't say," Justice Crennan said.
