Police early Wednesday said they had arrested a Czech man suspected of spreading HIV after a tip by a Phuket resident.
Officers said Zdenek Pfeifer, 52, was apprehended in the South, although the initial manhunt for the man had been in the North.
Mr Pfeifer, under a red notice by Interpol, is wanted in the Czech Republic for sexual offences with minors, including intentional passing on his HIV infection.
Police had earlier said Mr Pfeifer was believed to have passed his infection to "several" Thai male and female partners.
Khaosod newspaper reported early Wednesday they had picked up the suspect while on routine patrol in Phuket.
Police said that while checking the parking lot of the Tesco Lotus department store in Phuket town, a man resembling Mr Pfeifer's description rode a motorcycle into the area.
A policeman conducted a search and found the man inside the store. He called for backup, but found he had to "urgently use the restroom", and the suspect fled when he was inside.
Officers found him again within hours at a house he had rented.
EARLIER REPORT
Police in the North are searching for a Czech man, an over-stayer believed to be infected with HIV and wanted for sexual offences against minors in his own country.
The Royal Thai Police Office recently issued an urgent order asking Provincial Police Region 5 to track down Zdenek Pfeifer, 52, a national of the Czech Republic.
Mr Pfeifer, named in a red notice issued by Interpol, is said to be HIV-infected and to have passed the infection on to several male and female partners in Chiang Mai and nearby provinces, Thai media reported on Tuesday.
Pol Maj Gen Pongdet Prommichit, deputy chief of Provincial Police Region 5, on Tuesday called a meeting with police in eight northern provinces under his office and instructed them to immediately find and arrest the Czech suspect.
Pol Gen Wut Liptapanlop, deputy national police chief, had asked police across the country to track down Mr Pfeifer, suspect No 26 on the arrest warrant issued by the Czech court, said Pol Maj Gen Pongdet.
The man is regarded as dangerous and believed to have spread HIV to male and female Thai partners. He had committed sexual offences against minors in the Czech Republic before fleeing to Thailand in 2014, the deputy chief of Provincial Police Region 5 said.
According to police investigators, he has flown to several major tourist attractions in Thailand but there was no record of his having left the country.
Pol Maj Gen Pongdet said police believe the man is still here.