Thai authorities say a senior police officer who was arrested recently under a law that protects the royal family has died after he was found hanging while in military custody.

The Department of Corrections said in a statement that Maj. Prakrom Warunprapa hanged himself using a piece of cloth from his prison uniform on Friday.

Saturday's statement said the prisoner was still alive when a security guard found him and rushed him to a hospital. A doctor later pronounced him dead.

Prakrom, a well-known fortune teller and a third person were arrested on Wednesday under the so-called lese majeste law, which makes criticizing Thailand's royal family or bringing it to disrepute punishable by up to 15 years in prison.