Police have arrested two UK nationals, one a fugitive from British law who became a boxer in Phuket and the other for illegally running a cosmetic clinic on Koh Phangan.
Ben Ransom, 28, was taken into custody at a restaurant in Phuket on Monday.
Police said Mr Ransom was wanted in Britain on charges of drug trafficking. He arrived in Thailand two years ago and fought in Phuket using the ring name “Billy”.
Mr Ransom denied all charges, but would be extradited, police said.
On Koh Phangan in Surat Thani province, police on Monday arrested Thomas Foley, 42, at a rented house for illegally operating a clinic, selling medicine, possessing unregistered medicine and working without a permit. It is alleged he illegally provided cosmetic "filler" injections.
Police seized cosmetic products worth about 3.5 million baht.