A 37-year-old Tokyo man has been arrested on suspicion of operating a teen prostitution ring and forcing high school girls to sell the anti-impotence drug Viagra to their customers, according to police.

Kazuhito Naganuma of Nakano Ward allegedly acted as a pimp for about 30 high school girls and instructed the teenagers to sell Viagra at 10,000 yen per tablet. The drug, which was authorized by the government last month, requires a prescription for purchase.

Police have also arrested a 52-year-old business owner from Tokyo's Kita Ward for soliciting sex from one of the girls in violation of the metropolitan ordinance against prostitution, they said. Naganuma was arrested for introducing the 16-year-old girl to the man on Dec. 3 at a hotel in Tokyo's Shinjuku Ward, they said.

The man, whose name was withheld, allegedly paid the girl 30,000 yen and Naganuma a 10,000 yen tip.

Naganuma is suspected of launching the prostitution ring after meeting a high school girl in 1996 in Shinjuku. He allegedly expanded his business by exploiting the girl's network of friends.

Police said Naganuma paid the girls 5,000 yen for each new girl they introduced to the ring. They said the girls are known to have taken stimulant drugs provided by their customers.