Australian writer Harry Nicolaides has been sentenced to three years.
Nicolaides wrote a novel 4 years ago. This novel contained a brief passage referring to an unnamed crown prince. It was sold just 7 copies.
Nicolaides admitted the charge of insulting the royal family, but said he was unaware he was committing an offence.
Thailand's monarchy is sheltered from public debate by the world most stringent lese-majeste laws.
Harry Nicolaides was arrested when he was leaving the country. It was in August.
His self-published book "Verisimilitude", was hardly well-received. The only copy which is still known to exist sits on the shelf of the Thai National Library, and is available to the public.
Nicolaides pleaded guilty to the charges against him at Bangkok's Criminal Court on Monday, Jan 19.
