Narcotics Suppression Bureau (NSB) police found 60 million baht in cash in a safe at a condo rented by alleged drug gang boss Sadayu "Note" Luangpradabjai in Nonthaburi's Rattanathibet area.
The also found 10 submachine guns equipped with sound suppressors in the room.
Police searched the room at Lumpini Park Condominium on Thursday as they hunted down members of Mr Sadayu's gang who escaped an NSB raid on a Khao Yai resort in Nakhon Ratchasima's Pak Chong district early on Wednesday.
The raid followed a tip-off that Mr Sadayu, a former member of the notorious Oros drug gang who broke away and set up his own mob operating in Bangkok and surrounding provinces, was hosting a "seminar" and "thank you" party for his dealers at the Khao Yai resort.
Some fleeing gangsters headed to Saraburi province, where one of their vehicles was trapped by police after a long chase. One man was killed in an exchange of gunfire with police and another caught.
At the Khao Yai resort, police rounded up about 30 suspects and seized 172,000 methamphetamine pills, 11 kilogrammes of crystal meth, 520 bottles of ketamine, 1,450 ecstasy pills, 1kg of marijuana, about 33 million baht cash, an amount of jewellery, a large quantity of guns and ammunition, and other items worth altogether about 150 million baht, Rewat Klinkesorn, commissioner of the Narcotics Suppression Bureau (NSB) announced at a press conference on Thursday.
In a follow-up action, police searched a room rented by Mr Sadayu at Lumpini Park Condominium in Nonthaburi's Rattanathibet area and seized a 1.50-metre high safe.
When they opened it, they found 60 million baht cash inside. Ten submachine guns equipped with sound suppressors were also found in the room, Mr Rewat said.