The sex trade in Korea was estimated to amount to 14 trillion won (US$13 billion) last year, roughly 1.6 per cent of the nation's gross domestic product.

The Korean Women's Development Institute, commissioned by the ministry of gender equality on Sept 19 released a report on the sex trade.

"The official figures of the sex trade dropped compared to 2002 thanks to a continued crackdown on prostitution," said Byun Hwa-soon, a researcher at the think tank.

"But we cannot deny that new forms of prostitution and overseas sex tourism, which domestic authorities cannot police, have increased."

More than 46,000 brothels and disguised sex-service businesses disguised were identified last year, down 23 per cent from 2002, according to the report.

The number of prostitutes dropped by 18 per cent to 269,000 during the same period. The sex trade involved some 94 million transactions in Korea last year, down from 170 million in 2002.

The amount of money traded for prostitution was over 14 trillion won, much less than 24 trillion won in 2002.

About 21 per cent of the transactions were made in businesses claiming to be bars, karaoke clubs, massage parlors, barber shops or other businesses.

The Sept 19 report came five years after the ministry of gender equality and the Korean Institute of Criminology jointly conducted a research of similar scale for the first time. Under a new law against the sex trade that took effect in 2004, the government plans to issue such reports every three years.