A KAOSIUNG City-employed doctor and a friend in the pharmaceutical business have been arrested for allegedly paying underage girls in return for sex, the Criminal Investigation Bureau (CIB) said yesterday.

The suspects, both in their 60s, were nabbed separately at two motels in the southern city on Thursday with underage girls, the CIB said.

The doctor, Chen Che-wen, was arrested in a motel room with a 17-year-old girl, while his friend, Lin Chun-tsang, was caught with two girls, both aged 13, in another motel room, the CIB said.

The CIB said about a dozen underage girls are believed to have fallen victim to the two men's money-for-sex trick.

Following the arrest, the National Health Bureau has terminated Chen's contract for his service at Kaohsiung government-run outpatient clinics.

The CIB's field office in southern Taiwan started investigating the two suspects a few months ago after three underage girls claimed that they had sex with the pair in exchange for money.

According to the CIB, the girls said Chen and Lin had been paying girls for sex since 2008, with sums ranging from NT$5,000 to NT$10,000 (S$211 to $423).

CIB detectives had put the suspects under surveillance for a few months, during which they had often been seen taking underage girls to cafes.

But there had been no evidence of any illegal activity until Thursday, the CIB said.

The three girls found with the suspects on Thursday told the CIB that the two men promised them money in return for sex.