Angry local residents found a woman without underwear hiding under the stairs in the abbot's residence at a temple in Phra Pradaeng district on Wednesday night.
About 100 people who live near the temple stormed up to 65-year-old Phra Samut Prasartporn Mahapunyo's two-storey living quarters about 8.30pm.
They were angered by reports that a woman had entered the place earlier that evening and had not left.
The abbot refused to open his door to the mob until police arrived and persuaded him to stand aside.
The abbot insisted there was no woman there with him.
Then reporters spotted an elastic hairband on the abbot's bed and asked him to explain. The abbot said he used it to relieve headaches.
Back on the ground floor, people noticed a bra on the floor under the stairs, close to a rack covered with the abbot's robe. When the robe was removed, they found a woman crouching there.
People turned on the abbot and the woman, angrily cursing them. Police summoned reinforcements to help escort the couple out of the abbot's living quarters. Bottles of liquor were also found on the premises.
The abbot was expelled from the monkhood and then taken to the police station for questioning.
