Thirty macaques in bags and boxes were found in an empty building in Saraburi province police believe was used by wildlife traffickers.
Police raided the building after a passing motorist reported hearing loud animal noises as she drove by.
Police found 29 live macaques, either stuffed in plastic boxes in the living room or in bags hanging from a rope in the bathroom. Another was found dead outside the building.
Macaques are a protected wild animal.
Police said it was likely the macaques were left there by wildlife traffickers to avoid a vehicle search at a nearby police checkpoint.
The macaques were taken to a wild animal shelter in Nakhon Nayok province.
