"The king has granted permission to announce that Princess Srirasmi, the wife of Crown Prince Maha Vajiralongkorn, has informed in a written document that she has resigned from her royal status," the palace said in a statement.
"Acknowledgement and permission has been granted by His Majesty the King," the statement added.
Princess Srirasmi married the Crown Prince in 2001. The couple has a son who is thought to be Vajiralongkorn's most likely heir.
Thailand has been awash with rumors of Srirasmi's fate for weeks after a slew of her relatives were caught up in a widening police corruption scandal that has sent shockwaves through country's elite.
Several high profile figures have been arrested including a host of senior policemen and military officers, while one of Thailand's richest men is on the run from police on charges relating to the probe.
But reportable facts on Srirasmi's status were scant.
The country's monarchy is protected by some of the world's strictest lese majeste laws. Both local and international media must heavily self-censor when covering the country's royal family.
The first indications that her royal status could be in doubt came earlier this month when the Crown Prince announced that members of her family had been forbidden from using the surname "Akkharapongpricha".
At least three relatives with that surname were arrested in the corruption scandal, and the name represents an honorific title given to some of Srirasmi's family following her marriage to the prince.
Many of the more than 20 detained have been charged for defaming the monarchy, with police saying they had made "false claims" about their relationship to a royal to justify committing crimes that allegedly ranged from running illegal casinos to oil smuggling, kidnapping and extortion.
In recent days there were increasing signals Srirasmi was no longer part of the royal family.
In an unusual break from tradition, there was no mention of her in the royal household news broadcasts on December 9, her birthday.
The next day she disappeared from the opening sequence of the nightly royal news broadcasts which features portraits of all the kingdom's senior royals.
The princess was last seen in public on December 6 when she presided over the 9th anniversary of her pet project, an organization called "The Family Bond Project".
The report on the Ministry of Education website says the project "aims to promote and strengthen love and learning between all family members".
source: www.abs-cbnnews.com
