The Thai monarch's most beloved dog has died, just days after a man was arrested under the country's harsh royal defamation laws for allegedly a making satirical online comment about arguably Thailand's most popular pet.

Tongdaeng (Copper), as the dog was called, gained instant celebrity status in Thailand after King Bhumibol Adulyadej adopted her as a stray puppy and detailed her attributes in a book in 2002.

King Bhumibol praised her for her loyalty and obedience in the book which was then widely seen to contain teachings about how Thais should live and remember their place within the kingdom's rigid society.

The dog's death was announced in a statement from the veterinary faculty of Kasetsart University late Monday.

According to the statement "Khun Tongdaeng" died while sleeping on December 26 at Klai Kangwon Palace. The 17-year-old dog had not been keeping well for the last few years.

"Khun" is an honorific in Thailand, roughly translating to "ma'am;" it was frequently used by officials and local media when referring to Tongdaeng.

The royal dog, regularly seen at the side of King Bhumibol, was often featured in palace photographs. The book about her sold more copies in Thailand than bestsellers such as Harry Potter. A privately-funded animated film based on the white-and-beige-colored dog's life is currently showing at Thai cinemas.

Harsh defamation laws

The dog's death comes just days after a factory worker was charged for making what his lawyer describes as "sarcastic" online remarks about the royal canine. The worker, also facing charges of sedition and insulting the king, could face a total of 37 years in prison for his social media posts.

The arrest has once again brought to the fore the debate about Thailand's royal defamation laws, among the harshest in the world. The defamation laws are aimed at shielding the monarchy from any debate and criticism.

Anyone convicted of insulting the king, queen, heir or regent, can face up to 15 years in jail on each count.

The case also underscored the fact that boundaries for what counts as a royal insult have also expanded dramatically since the army, which styles itself as the champion of the monarchy, grabbed power in a coup last year.

King Bhumibol, the world's longest reigning monarch, currently resides at a Bangkok hospital where he has been treated for various ailments over the past several years.

He turned 88 in early December amid growing concerns over his health; although Bhumibol has a clear heir in Crown Prince Maha Vajiralongkorn, his less popular status among Thai people has prompted concerns over the royal succession in post-coup Thailand.

ap/msh (AFP, dpa)