A German man living in northern Thailand claims to have infected dozens of local women with the HIV virus.
Mr Schiemann has lived in Thailand for several years
Hans-Otto Schiemann, 56, says he is HIV-positive and has paid women in the town of Chaiyaphum for sex.
A provincial health officer said Mr Schiemann's actions put up to 90 women at risk of contracting the disease.
Mr Schiemann appeared in court on Monday charged with overstaying a tourist visa. Thailand has no laws to tackle deliberately spreading HIV-Aids.
The former sailor, who has one leg and is living off a disability pension, has refused to take an HIV test to confirm his claims.
He is accused of offering the town's young women large sums of money to have sex with him.
Residents in Chaiyaphum said Mr Schiemann offered students aged from 15 to 17 around
4,000 baht ($100) for sex.
Officials have since put up posters around the town, 340 km (210 miles) northeast of Bangkok, warning women to avoid him.
Residents believe Mr Schiemann, whose Thai wife has Aids, has been waging a campaign of vengeance against Thai women whom he blames for infecting him.
"Thai women are bad. Thai women are witches and they're monkeys," he told reporters outside the provincial court in Chaiyaphum on Monday.
"I'm a playboy. I'm a rich man. Everybody likes a rich man," he said.
Thai officials say they are powerless to prosecute Mr Schiemann on allegations of deliberately spreading HIV.
Instead he has been remanded in custody on immigration offences, and will reappear in court on 15 November.
He faces deportation or two years in jail if found guilty.