Acting on a tip-off, the Crime Suppression Division raided a house in Bang Bua Thong district, seizing gambling tables, chips and cash.
The illegal casino was also operating in defiance of government public safety measures in line with the ongoing COVID-19 pandemic.
Of the 40 arrested, 33 were Thai gamblers, while the other seven were migrant employees. All 40 suspects were taken to Bang Bua Thong Police Station for interrogation and for COVID-19 screening.
Police said the house had been used as a gambling den for the past two days and that they are working to track down its owner, who had plans to move the operation to other locations periodically.
“Officials have arrested 40 persons, 33 are Thai nationals and seven are migrant workers of the casino,” said Pol Maj-General Jiraphop Phuridet, deputy chief of the Central Investigation Bureau.
“Officials have also confiscated decks of cards of the Dragon-Tiger game, plastic chips and some cash as evidence.”
The arrests come just days after 21 people were arrested on charges of illegal gambling following raids on five venues in Bangkok.
Speaking after the arrests, Phuridet said: “This operation is part of the National Police chief’s policy to eliminate gambling dens nationwide, to reduce the risk of COVID-19 spreading among the public.”