06/02/2014 02:43 EDT | Updated 06/02/2014 02:59 EDT

Kate Middleton, The Duchess Of Cambridge, Makes Alleged Dorchester Hotel Visit

AFP via Getty Images
Prince William's girlfriend Kate Middleton arrives at the Sovereign's Parade at The Royal Military Academy in Camberley, west of London, 15 December 2006. Prince William was among the 446 officer cadets on parade, of which 227 passed out receiving their commision and becoming officers. Prince William is to join the Household Cavalry in The Blues and Royals. (Photo credit should read BEN GURR/AFP/GettyImages)

Kate Middleton's alleged visit to a London hotel last week has been deemed "particularly offensive."

The Duchess of Cambridge is accused of breaking a celebrity boycott after sneaking into the Dorchester hotel in London's Mayfair to attend her cousin's wedding, according to the Daily Mail.

The hotel is part of the Dorchester Collection group, owned by the controversial Sultan Hassanal Bolkiah of Brunei, who has imposed the sharia law in his country, making it legal, for example, for homosexuals to be stoned to death.

"It is hugely disappointing that the Duchess is still going to the Dorchester while so many other public figures are boycotting it," veteran gay rights campaigner Peter Tatchell told Huffpost UK News.

Vogue's Anna Wintour, Richard Branson, Paul and Stella McCartney have all joined the worldwide boycott to avoid hotels owned by the sultan, and Kim Kardashian moved her bridal shower from the Beverly Hills Hotel for this very reason, reported E!. Other boycotted venues include LA's Hotel Bel-Air and Paris' Le Meurice.

According to an insider, the Duchess secretly slipped into the hotel through an underground car lot using a blacked-out car. Her first cousin, Adam Middleton, was getting married there.

Over the weekend, Prince William and Harry also faced a backlash after they were photographed playing polo at Coworth Park in Berkshire, another hotel owned by the Sultan. In April, actor Stephen Fry cancelled his stay at Coworth after learning about the hotel owner's views on gay rights.

However, the young royals weren't the only ones to make headlines over their hotel visits: Mariah Carey sang at a New Year's party for the sultan's son, and Russell Crowe was attacked on Twitter for his stay at a Beverly Hills hotel.

In response to the international boycott, the hotel said it had "no involvement in this religious and political issue.”

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