A 36-year-old Russian who admitted smuggling hashish from Bhutan by putting it in condoms he then swallowed has been arrested on Koh Phangan, police said.

Tourist police on Tuesday evening detained Denis Bichuk after he parked a motorbike in front of a supermarket in tambon Koh Phangan.

When questioned by police Mr Bichuk was seen to be sweating, talked rapidly and trying to cover his crossbody bag.

A search found 9.42 grams of cocaine and 13.56g of magic mushrooms, along with 415.72g of hashish - a concentrated form of cannabis - packed in four condoms.

Mr Bichuk allegedly told police he picked up packed hashish in Bhutan and ate it to avoid the customs check. He excreted the condoms after arriving on the resort island and was selling the hash to other tourists. 

Mr Bichuk said he bought the cocaine from a foreigner on the island for 4,000 baht per gram.

Police have charged him with illegal possession.