Authorities have cut internet cables found to be illegally carrying services from Mukdahan province across the Friendship Bridge and about five kilometres deep into Laos.
The service was believed used by scam gangs based in Laos to trick Thai victims into believing they were dealing with callers and businesses based in Thailand.
The illegal cable link was discovered on Sunday.
The cables were strung across the Second Thai-Lao Friendship Bridge linking Mukdahan province and Savannakhet province in Laos across the Mekong River.
The cables were installed by a company the NBTC had licensed to provide telecommunications services only in Thailand.
Police said the case was unusual, as officials often found internet cables laid along natural border crossings and over rivers. This is the first time police found cables installed on a cross-border bridge, they said.
