Thalang Police were called to the room by the property owner at 4:30pm on Friday (June 7).
The property owner explained that the room was last rented out to a Ms Chonthicha Nonthichan since Oct 1 last year for B2,500 per month.
However, Ms Chonthicha had failed to pay her rent for three months, for March, April, and May this year.
Unable to contact Ms Chonthicha, the property owner had filed a report with Thalang Police before changing the lock at the end of May.
The landlord entered the room last Friday to prepare it for a new tenant, and found the stash of meth pills on the floor.
Police are continuing their investigation into the origin of the pills and trying to track down Ms Chonthicha.