Police arrested a 37-year-old man and seized his collection of about 20 guns and 1,661 bullets at his luxury house in Pak Kret district on Thursday.
Pol Col Surachet Bundit, deputy commander of the Patrol and Special Operation Division, said Kritchanayot Akapram had pistols, rifles and shotguns at his home, house 54/20 in Moo 3 village of tambon Khlong Khoi.
Police searched his home after arresting the administrator of the AP-YanyonFaceook page website, which illegally sold guns on the internet.
The suspect was an illegal gun collector, Pol Col Surachet said.
Pol Col Piyarat Suparat, superintendent of the division, quoted Mr Kritchanayot as saying he was a garment vendor at a shopping centre, and also an enthusiast of guns and shooting sports.
He bought his guns on the net at prices of 10,000-20,000 baht each.