A woman returning home from a trip to Brazil was found to be carrying about 50 small packages in her stomach containing a total of 550g of cocaine after she was detained at Suvarnabhumi airport.
Tavorn Kamolma, 29, was held on Wednesday afternoon after arriving on a flight from Sao Paolo, police said.
Benja Louichareon, director-general of the Customs Department, said Ms Tavorn matched the description of a person an informant had told them could be smuggling drugs.
She was stopped and questioned and her luggage searched but nothing illegal was found. However, Ms Tavorn's speech seemed confused and it appeared she had an urge to vomit. She was taken to hospital, where an x-ray revealed the packages in her stomach.
The woman eventually confessed that she was paid 30,000 baht to carry the packets from Brazil. However, she said she was told they contained gems. She did not know it was cocaine, she said.
Ms Tavorn lamented that she took the job over the protests of her family because she thought it paid well.
She was charged with possession of a class 2 drug with intent to distribute and handed over to drug suppression police.
Police estimate that the drugs have a street value of around 1.65 million baht.