Thailand ? A few lines in a novel that sold just seven copies have earned an Australian writer three years in a Thai prison.

The conviction of Harry Nicolaides on Monday for insulting the monarchy is one of a recent flurry of such cases, underlining Thailand’s sensitivity about how to safeguard the royal institution when 81-year-old King Bhumibol Adulyadej — the world’s longest-serving head of state — passes from the scene.

Nicolaides, 41, was sentenced for insulting the king and Crown Prince Vajiralongkorn in his self-published 2005 book “Verisimilitude,” which he has said sold seven copies.

Shackled at the ankles and handcuffed, Nicolaides said he felt “dreadful” as guards escorted him out of the courtroom.

“I would like to apologize,” he said, adding that he had “unqualified respect for the king of Thailand” and had not intended to insult him. He said he endured “unspeakable suffering” during his pretrial detention, but did not elaborate.

The offending passage in the novel — described by Nicolaides as a commentary on contemporary Thai political and social life — was just a few sentences long and described the turbulent marital relations of its fictional prince.

The passage “suggested that there was abuse of royal power,” and caused “dishonor” to the king and the heir apparent, the presiding judge told the court.

The prosecutor warned reporters Monday that the law prohibited publication and repetition of the material.