They released most of them by cutting open the bags before reporting their discovery to police, Wirom said.
The Department of National Parks did not immediately respond to a request for comment.
Officers from the parks department arrived to collect the remaining monkeys and take them to a wildlife quarantine centre near the capital, Bangkok, Nation TV said.
Thailand and the wider Southeast Asia is home to some of the world's most diverse flora and fauna, but the region has suffered from rampant poaching and trafficking of wildlife.
The pandemic halted much of the lucrative trade, but it is now picking back up as countries lift border restrictions, according to the United Nations.