Zdenek Pfeifer, 49, was detained at his apartment on the island of Phuket on Tuesday evening, Thai Interpol said in a statement.
His arrest came after reports warning of his presence in the popular holiday nation went viral on Thai social media this week.
“Thai police will contact Czech Interpol once he has been prosecuted for local violations,” Thai Interpol said, adding he was arrested for illegally overstaying his visa.Czech media reports said Zdenek fled the country in June 2015 after he was charged with deliberately infecting more than a dozen men with HIV, including a minor.
Colonel Krissana Pattanacharoen, Thailand deputy national police spokesman, said Pfeiffer faced “sex offence” charges back home.
He first entered Thailand in June 2015 on a tourist visa which ran out in August of that year.
“Along the way we received the red notice from Interpol and police arrested him yesterday for overstaying,” he told AFP.
Lieutenant-General Nathathorn Prousoontorn, commander of Thailand’s immigration police, told reporters that there was currently no complaint filed locally that Pfeiffer had knowingly infected anyone with HIV.
Phuket is a hugely popular southern Thai island known for its many resort hotels as well as a seedy red-light district centred around Patong Beach.