Prince Jefri Bolkiah, the 55-year-old younger brother of the Sultan, is seeking to persuade a judge in Manhattan that pictures of the four statues should not be shown to a jury that will consider his lawsuit against former legal advisers.

He has also said the jury should not be told that he had several wives and mistresses, because “polygamy is offensive to many Americans”.

The statues were once kept on the prince’s 28-acre estate on Long Island, New York. Mark Cymrot, a lawyer for one of the defendants in the lawsuit, said: “They make me blush. They’re very explicit”.

The prince’s lawsuit, separate from the long-running legal dispute with his brother, accuses the advisers of mishandling his wealth and cheating him out of $7 million (£4.3 million).

His lawyers said in court papers that Faith Zaman, who is being sued with her husband Thomas Derbyshire, obtained the photos of the statues “in order to embarrass” him.

They also argued that details of love life should be excluded. “Prince Jefri was entitled to have multiple wives and families, and he did so,” the court papers said. “Under Islamic law and practice this was legitimate and proper.

“However, polygamy is offensive to many Americans, and trial testimony about Prince Jefri’s personal life may be prejudicial to him.” The legal dispute between the sultan and the prince centres on the younger brother’s alleged embezzlement of $15 billion (£9 billion) after being put in charge of much of the oil-rich kingdom’s wealth.

It has been dragged through courts in London, Malaysia and the Cayman Islands over the past decade.

In 2007 the Privy Council – the final court of appeal for Brunei, a former British protectorate – ruled in support of a 2000 judgment ordering the prince to give his assets to his brother and live on a “monthly allowance” of $300,000 (£185,000).

The assets included billions of pounds, hundreds of international properties including New York’s Palace Hotel, thousands of cars, artworks by Picasso and Renoir and a 180-foot yacht called Tits.

Mr Cymrot said the defendants “stole nothing”. He added: “Jefri is trying to blame them for his own conduct in connection with his dispute with the sultan.”