Bangkok (AFP) - The US Ambassador to Thailand is facing a police investigation for royal defamation after criticising jail terms under the draconian law, as ultra-nationalist sentiment surges since royalist generals seized power.
Under Thai law anyone convicted of insulting the king, queen, heir or regent can face up to 15 years in jail on each count.
Prosecutions have soared since the army, which tags itself as the champion of the monarchy, grabbed power last year.
Record breaking sentences have been handed down in recent months to transgressors, most of whom are regime critics but also include senior officials swept up in nebulous corruption probes.
The Foreign Correspondent's Club of Thailand (FCCT) said it had been asked to cooperate in the probe against US Ambassador Glyn T. Davies.
Police are probing whether a speech he delivered to international media last month at the club "violated article 112 of the criminal code, the lese majeste law".
"The FCCT is cooperating with the police," the club added in a statement.
A senior Thai police source confirmed to AFP that they had received a complaint and were investigating the ambassador's comments.
In a wide-ranging talk to the FCCT, Davies heaped praise on the revered but ailing 88-year-old Thai King Bhumibol Adulyadej.
But he also expressed concern at the "unprecedented prison sentences handed down by Thai military courts against civilians" for alleged lese majeste.
"We believe no one should be jailed for peacefully expressing their views and we strongly support the ability of individuals and independent organisations to research and to report on important issues without fear of retaliation."
A video of the speech is available on the FCCT's YouTube site.
- Envoy misquoted? -
In Thailand any member of the public can make an allegation of royal defamation and police are duty bound to investigate.
Critics of the law say that situation often results in effective witch-hunts, led by ultra-nationalist volunteers who comb through social media and public events for possible breaches of the law.
In recent years the law has also been increasingly broadly interpreted.
Historians have even found themselves facing complaints, often filed by ultra-nationalists, over their writings on past Thai monarchs.
All Thai-based media must heavily self censor when reporting on the monarchy and even convictions under the lese majeste law for fear of falling foul of the law.
Ambassador Davies' comments centred on criticism of the royal defamation law, not the royal family.
Davies spoke for more than an hour at the club on Washington's long relationship with Thailand, saying Washington respected and admired Bhumibol.
"We think he has done so many, many wonderful things not just for Thailand but for the United States and for the region," he said.
But he added Washington was alarmed by recent convictions under the lese majeste law.
AFP has seen a police document detailing the complaint which requests a DVD of Davies' comments as well as a list of names of those who attended the event.
The complaint is made by a member of the public and appears to be based on mistranslated quotes of his English comments.
The letter erroneously says Davies told the audience Washington would help independent organisations research lese majeste "so that they are not afraid".
Ultra-nationalists seized on his remarks and organised a protest led by a firebrand monk outside the American embassy in Bangkok two days later.
Notoriously prickly Thai junta chief Prayut Chan-O-Cha also threatened trade ties with Washington if the ambassador repeated such criticism.
Like all foreign envoys, ambassador Davies has diplomatic immunity so it is unlikely the probe will lead to an arrest. However, Thailand can rescind his credentials at any time.
The US embassy could not be immediately reached for official comment.