Thailand mulls legal prostitution

Garish signs over Bangkok's girlie bars and massage parlours openly advertise an industry comprising an estimated 3 per cent of Thailand's economy.

But prostitution is technically illegal, pays no taxes, fosters police corruption and treats its workers like slaves.

Clearly, the government says, it's time to open a debate on legalising and regulating the sex business.

The Justice Ministry will hold an unprecedented public discussion of its proposal to legalise prostitution and register sex workers.

"We (will) tackle this problem one way or another," Justice Minister Pongthep Thepkanchana said in a recent interview. "Maybe we will approach the problem of prostitution differently than we do now."

Taxing the estimated $US4.3 billion ($A6.0 billion)-a-year trade could give a big boost to government coffers.

Legalisation would give the estimated 200,000 sex workers access to social services, health care and protection from abuse while exposing corruption among the industry's gatekeepers - police, politicians and business owners, proponents say.