US 'worried over Thai succession'
American diplomats have expressed concern over Thailand's royal succession, according to leaked cables.
The documents suggest Crown Prince Vajiralongkorn, who is next in line to the throne, is suffering from health problems. US officials are also worried about how the Thai public regards him.
His father, 83-year-old King Bhumibol Adulyadej, has been in hospital for much of the past two years.
Thailand has strict laws prohibiting any criticism of the monarchy.
Offences under lese majeste laws are punishable by up to 15 years in prison.
The concerns of the US embassy officials were publicised by journalist Andrew MacGregor Marshall in several British newspapers.
He left his job at Reuters news agency because they would not publish the claims.
He told the BBC: "The Thai people - most of them - genuinely love and respect King Bhumibol. It's not fake.
"They really do love him and they are very protective of him and that, I think, has caused people to be against anybody saying anything that appears to attack the monarchy."
But he said that the military and palace courtiers had been meddling in politics for years.
"And they have somehow allowed themselves to hide under the same umbrella of lese majeste as the king," he said.
The documents, publicised just days before Thailand's general election, were reportedly written by US diplomats over several years.
They air concerns about the prince and how he is perceived in the country, suggesting that Thailand will face "a moment of truth" when the king dies.
One embassy cable in 2009 is quoted as saying: "It is hard to overestimate the political impact of the uncertainty surrounding the inevitable succession crisis which will be touched off once King Bhumibol passes."
Many of the issues raised in the cables are known about and discussed privately in Thailand.
But there is a taboo around their public discussion in the country.