Adisak Phromsila from Karon Municipality said that Karon Police received calls from concerned citizens reporting the incident at 2:20pm.
Officers responded and questioned the monk, Phra Manop Nonthakho, 67, originally from Nakhon Sawan province.
Phra Manop explained that he had travelled to Phuket from Phattalung province. He explained that he had gone for a dip in the water to assuage itchiness brought on by a skin condition he had.
He did not fully undress. He kept on his half-length robe and went to play in the water, as evidenced by a video posted later online.
After his stop at Karon Beach, Phra Manop started his trek northwards towards Patong. He said he would be staying a temple in Thalang District, but added that he did not know which one.