A Thai celebrity fortune-teller accused of insulting the monarchy has died in custody, authorities said Monday, becoming the second person in connection with the high-profile case to die behind bars.

The fortune-teller, Suriyan Sujaritpalawong, known by the name "Mor Yong," died of a blood infection Saturday at the military prison where he had been detained since mid-October, the Justice Ministry said.

Mor Yong was known as a fortune-teller popular with the Thai elite, and his death sparked immediate skepticism on social media about why authorities waited two days to reveal his death.

The military regime that ousted an elected civilian government last year has declared that defense of the monarchy is its priority, and it has vigorously pursued prosecutions under the law, trying such cases in military courts. Lese majeste, or insulting the monarchy, is punishable by 3 to 15 years in prison.

Justice Minister Gen. Paiboon Koomchaya told a news conference Monday that Suriyan had died of a personal health problem that had required medical treatment several times during his detention.

The Corrections Department said in a statement that a guard found him unconscious in his cell bed Saturday night and sent him to the prison hospital, where he was pronounced dead. An autopsy identified the cause of death as septicemia, which is also known as sepsis and is a life-threatening condition that can occur from bacteria in the blood.

The announcement of the death came two weeks after a senior police officer also implicated in the case allegedly hanged himself while in custody.

They were among three suspects arrested last month in a widening case involving people who allegedly exploited ties with the monarchy for personal enrichment. The third suspect, Suriyan's assistant, is still in custody.

Police say they are seeking more suspects, and Thai media have been filled with unconfirmed reports of high-ranking military officials under suspicion.

The case focuses on sponsorship of mass biking events arranged to honor Thailand's king and queen, and accuses the suspects of allegedly seeking kickbacks and other benefits in connection to the events.

Police corruption is a long-standing problem in Thailand, but it rarely has involved charges of lese majeste.

The case is similar to one late last year in which a high-ranking police officer and many accomplices were charged with lese majeste and found to be unusually wealthy. The officer, former Central Investigation Bureau chief Pongpat Chayaphan, was related to relatives of Princess Srirasmi, the then-consort of Crown Prince Vajiralongkorn, who shortly afterward lost her royal title and separated from him.

Thai politics for the past decade have been overshadowed by concerns about the eventual succession to King Bhumibol Adulyadej, the world's longest-reigning monarch, who is 87 years old and ailing.

The Associated Press contributed to this report.