The Central Investigation Bureau (CIB), working with the Crime Suppression Division (CSD), Immigration Bureau and the Royal Thai Police Anti-Trafficking in Persons Centre, announced the arrests this week following raids in Bangkok and at the Bangkok Southern Bus Terminal.
Police identified the suspects as Ms Kanyarat, Nigerian national Mr Chiadikaobi, and Ms Somporn. All three face charges of jointly possessing Category 1 narcotics (heroin) with intent to sell without permission, for commercial purposes and in a manner deemed harmful to public safety and national security.
Authorities said the network was smuggling heroin into Thailand for distribution in major tourist destinations, including Bangkok, Pattaya and Phuket.
The investigation began after Nong Khai Immigration Bureau officers received intelligence about a Nigerian-led drug trafficking operation working with Thai women in Bangkok.
Police said one of the Thai suspects had illegally crossed into a neighbouring country through a natural border route before returning to Thailand and checking into a hotel in Bangkok.
Investigators later raided the hotel and arrested Mr Chiadikaobi, who was allegedly found with 49.5kg of heroin concealed inside snack bags in an attempt to avoid detection.
The investigation was then expanded, leading to the arrest of Ms Somporn at the Bangkok Southern Bus Terminal while she was allegedly attempting to transport drugs to Phuket. Officers seized an additional 16kg of heroin hidden in snack and pet food bags.
In total, officers seized 65.5kg of heroin with an estimated street value of more than B200 million.
The CIB also issued a warning to Thai women about online romance scams involving foreign nationals who persuade victims to receive or transport packages across provinces or international borders.
Police warned that unsuspecting women could become involved in transnational drug trafficking operations and face severe penalties under Thai law, including possible capital punishment.
The operation was conducted under the direction of senior officers including Pol Lt Gen Natthasak Chaowanasai, commander of the Crime Suppression Division, and Pol Maj Gen Pattanasak Bubphasuwan, commander of the CSD, along with officers from Division 1 of the CSD, the Immigration Bureau and the Anti-Trafficking in Persons Centre.