Thai police on Friday questioned the wife of a British journalist over his social media links to unflattering photos allegedly of the kingdom's crown prince, in a country where insulting the royals carries heavy jail terms.
Detectives said the photos shared by former Bangkok-based correspondent and strident Thai monarchy critic Andrew MacGregor Marshall were fake and violated the kingdom's royal defamation law.
On Friday Marshall's wife, 39-year-old Noppawan Bunluesilp, was taken into police custody in Bangkok and released without charges after several hours of questioning over her husband's social media posts from the day before.
"Based on forensic evidence, we determined she has nothing to do with (the case)," Thitirat Nongharnpitak, commander of the Central Investigation Bureau (CIB), told reporters after the interrogation.
"She is still a Thai who loves the institution," he added, using a euphemism for the monarchy.
The Facebook and Twitter posts published by Marshall, who lives outside Thailand, linked to a web article in German tabloid Bild with photos apparently showing 63-year-old Crown Prince Maha Vajiralongkorn at an airport in Germany.
On Friday morning the online article was blocked in Thailand for carrying "inappropriate content".
Under Thai law each count of lese majeste -- insults, threats or defamation of Thailand's leading royals -- carries up to 15 years in jail.
Local and foreign media based inside the country, including AFP, must routinely self-censor to avoid falling foul of the law.
"The pictures were doctored," Thitirat told AFP ahead of the questioning.
"The culprit is Andrew MacGregor Marshall who has violated lese majeste laws for several years," he said, adding "he has acted from overseas to attack" the royal family.
Marshall is an outspoken critic of the Thai monarchy and has written a book on the subject which is banned inside the kingdom.
He regularly posts commentary on social media that would be swift grounds for prosecution under the lese majeste law.
"The key point is my wife is not involved at all in my journalism," he told AFP from Hong Kong Friday.
"We'd always been concerned that it might be dangerous for my wife to visit Thailand especially since the military coup but she hadn't seen her family for a couple of years," he added.
The issue comes during a time of intense sensitivity surrounding the Thai royals, as the health of revered 88-year-old King Bhumibol Adulyadej wanes.
Lese majeste prosecutions have soared under the arch-royalist junta that seized power two years ago and styles itself as a defender of the monarchy.