Brunei’s sultan has stripped his daughter-in-law of all titles, saying her conduct was “unbecoming” of a member of the royal family.

The Office of the Grand Chamberlain of Brunei Darussalam confirmed earlier this month that the titles were revoked with “immediate effect” following a decree from Sultan Hassanal Bolkiah.

“The revocation was carried out following conduct by Pengiran Raabi’atul Adawiyyah that was deemed unbecoming of a spouse of a member of the royal family. Her actions were also found to have tarnished the monarchy’s good name and demonstrated a lack of respect towards Sultan Haji Hassanal Bolkiah,” it said in a statement.

Pengiran Raabi’atul Adawiyyah, 33, is married to Prince Abdul Malik, 43, who is the fourth in line to the throne.

Her actions showed a lack of respect for the sultan and damaged the monarchy’s reputation, the public broadcaster RTB News reported, without providing details of what she had allegedly done.

The Office of the Grand Chamberlain didn’t elaborate on the princess’s “unbecoming behaviour” either.

Raabi’atul Adawiyyah has lost the title of Yang Amat Mulia Pengiran Anak Isteri.

Observers noted that this wasn’t the first time the sultan had stripped someone of royal titles. In 2003, he stripped his second wife, Mariam Abdul Aziz, of her royal titles after their divorce.

He did the same after divorcing his third wife, Azrinaz Mazhar Hakim, in 2010.

But Raabi’atul Adawiyyah’s case is different. She is married to the sultan’s son and, thus, still a member of the royal family. There has been no official announcement of a divorce between them.

Raabi’atul Adawiyyah married the prince in 2015 in a lavish ceremony at the royal palace in the capital Bandar Seri Begawan. The celebrations lasted 10 days and were attended by thousands of guests.

The couple have four children – Princess Muthee’ah, 10, Princess Fathiyyah, eight, Princess Khaalishah, six, and Princess Nabeelah, who is 16 months old – whose titles have reportedly not been affected.

Prince Abdul Malik is the sultan’s son from his first wife, Queen Saleha. He is one of the monarch’s 12 children from three spouses.

Sultan Hassanal Bolkiah, 80, rules over an absolute monarchy in Brunei, a tiny oil-rich country on the island of Borneo surrounded by Malaysia.

Crowned the 29th sultan in 1968, he is the world’s longest reigning monarch and resides in the world’s largest residential palace with 1,788 rooms called Istana Nurul Iman.

Under his rule, Brunei has solidified its status as one of the world’s richest nations.