Two top police officers embroiled in a high-profile corruption scandal in Thailand kept an illicit fortune that included antique paintings, golden postage stamps and tens of millions of dollars in cash hidden in secret vaults at a dozen private residences, authorities said Wednesday.

Investigators found the goods stowed behind brick walls they had to break down and buried inside underground vaults on properties owned by the officers in Bangkok and the city's outskirts, said Col. Akkaradech Pimolsri, who heads the police Crime Suppression Division.

"Only a few people in Thailand could possess things as rare as this, like golden postage stamps and an ancient Buddha image," Akkaradech said.

Also found on properties owned by former Central Investigation Bureau chief Lt. Gen. Pongpat Chayapan and one of his subordinates, Col. Kowit Muangnual, were land deeds, illegal ivory, golden amulets and other antiques, police said.

Pongpat and Kowit are among eight police officers who have been arrested on charges ranging from bribery to defaming the monarchy, a grave crime in Thailand which carries a penalty of up to 15 years in prison. Police are searching for two other suspects and investigating several more.

Some of the suspects are alleged to have invoked claims of links to the royal palace in carrying out their wrongdoing, but National Police Chief Somyot Pumpanmuang declined Tuesday to elaborate. He said that Pongpat, the highest-ranking suspect, had confessed to all charges, including soliciting bribes for job appointments and allowing illegal gambling and oil smuggling.

Thailand's police department has a reputation as one of the country's most corrupt institutions.

The junta that has ruled the country since toppling an elected government on May 22 claims it is prioritizing the fight against corruption, but critics say graft remains institutionalized and the army's real goal is to cripple political rivals led by self-exiled former Prime Minister Thaksin Shinawatra, who was ousted in a 2006 coup.