Hanoi  - Vietnamese police have arrested a woman for procuring call girls who masqueraded as university students, a police official said Thursday.

Police in Ho Chi Minh City arrested Le Thi Anh Tuyet, 29, on Wednesday after surprising four couples engaged in liaisons she arranged at a hotel.

Mai Van Tan, director of Ho Chi Minh City's Department of Social Order Crime Investigation, said Tuyet, a former sex worker herself, had advertised that the 20 call girls in her employ were university students to attract customers.

"Customers are prepared to pay higher prices for students than for professional sex workers," said Tan.

The newspaper Ho Chi Minh City Law reported Tuyet had charged customers 100 dollars per encounter, and taken a 23 dollar cut for herself. Clients from northern Vietnam who requested Southern students, or vice versa, were charged up to 500 dollars.

"Customers prefer students to professional sex workers because students look cleaner and more innocent," said Le Bach Duong, director of Vietnam's Institute for Social Development Studies. Duong said students were considered less likely to carry sexually transmitted diseases.

Police said Tuyet had also arranged work in Singapore, Malaysia and Hong Kong for call girls in her service.

Under Vietnamese law, if convicted, Tuyet would face between six months and five years in prison.

At a conference Wednesday in Hanoi, Vietnam's Ministry of Labour, Invalids and Social Affairs reported that the age of sex workers in Vietnam is falling, with 18 per cent reportedly under the age of 18. (dpa)