Image copyright Getty Images Image caption The prince sent a letter to the interior ministry asking that his wife's family to be stripped of their royal name

Thailand's Crown Prince Vajiralongkorn has asked the government to strip his wife's family of their royally bestowed name.

It comes after seven of her close relatives were arrested in a purge of officials allegedly involved in corruption.

Princess Srirasmi Akrapongpreecha is Crown Prince Vajiralongkorn's third wife, and the pair married in 2001.

The move is widely expected to be a first step to divorce.

He was already known to be estranged from the princess, although they continued to attend official functions together.

Letter

The purge of Princess Srirasmi's family over the past 10 days has been widely reported in Thailand.

However, until now the severity of the lese majeste law criminalising any critical comment about the monarchy meant that no Thai media had pointed out the family connection.

The princess's uncle, a senior police general, was arrested over accusations of amassing vast wealth through smuggling and gambling rackets.

Four of her siblings and two other relatives have also been held.

The office of Crown Prince Vajiralongkorn has now sent a letter to the interior ministry ordering her family to be stripped of the royal name he bestowed on them when he married her.

The dramatic downfall of Princess Srirasmi comes at a very sensitive time, analysts say, with the 86 year-old King Bhumibol Adulyadej in poor health.

As the Crown Prince's wife, she would have been expected to become Queen when he succeeds his father, a potentially very powerful position given the exalted status of the monarchy in Thailand.

The pivotal position of the monarchy in Thailand's political order makes the succession an extremely sensitive issue, many aspects of which still cannot be reported from inside the country.

The world's longest-reigning monarch, King Bhumibol has been on the throne in Thailand since 1946.