Police freed 10 South Korean women from the brothel

Five people have been arrested and charged with offences including people trafficking and debt bondage.

Police said the women were lured to Australia and forced to work up to 20 hours a day in legal Sydney brothels.

They had agreed to work in the sex industry, but were deceived about conditions, police said.

"My understanding is that they came to Australia to work in the sex industry, but under more reasonable conditions," Australian Federal Police Assistant Commissioner Tim Morris said.

'Vanloads of men'

Once the women were in Australia, the syndicate took their passports, officials said.

"This is probably the largest alleged syndicate that we have smashed," Immigration Department Assistant Secretary Lyn O'Connell said.

The five people arrested include a South Korean woman and a Korean-Australian woman, who police allege is the head of a syndicate that was making $2.8m (£1.4m) annually.

Government prosecutors said the evidence against the five includes six months of intercepted phone calls and Korean-language business documents, Reuters news agency reported.

Prostitution is legal in most of Australia but new slavery laws were introduced in 1999 to prevent vulnerable women being exploited.

A business owner near one of the brothels said it was staffed by Chinese, Japanese and Korean women and was always busy, says the BBC's Phil Mercer in Sydney.

At the weekends, vanloads of Asian men would descend on the premises, he says.