The Royal Windsor Horse show, which has been attended this week by the Queen, is facing protests this weekend over the participation of a a Bahraini prince accused in the high court of torture.
BuzzFeed News understands that activists are planning a protest at the event over the appearance of Prince Nasser bin Hamad al-Khalifa, 28, whom the high court ruled was not entitled to diplomatic immunity over allegations of torture in 2014.
The prince has been accused of being involved in the torture of prisoners during a pro-democracy uprising in Bahrain in 2011. Gulf news sources claim that he will be competing in races at Windsor on Saturday. It is not known if the Queen will be in attendance, as she was earlier in the week.
The visit comes amid growing pressure on Bahrain over its human rights record, with international calls on the regime to release well-known activist Zainab al-Khawaja, 32, who is languishing in prison along with her infant son because she ripped up a photo of the king.
The Bahraini government says the claims about the prince's involvement in torture are untrue and politically motivated. However, in 2014 judges overturned a Crown Prosecution Service decision that the prince had state immunity from prosecution, meaning he could potentially be tried for torture in Britain. The Metropolitan police later concluded it did not have enough evidence to arrest him.
The court ruling, seen below, was brought by an activist known as "FF", who claimed to have been tortured by the kingdom's authorities (though not by Prince Nasser himself) after an uprising by Bahrain's Shiites in early 2011.
At the time, a Bahraini government spokeswoman said: "As Bahrain has never sought anonymity or sovereign immunity from the English courts for anyone in respect of this case, it expresses no view on the DPP's [director of public prosecutions's] statement that immunity was inappropriate.
"This has been an ill-targeted, politically-motivated and opportunistic attempt to misuse the British legal system. The government of Bahrain again categorically denies the allegations against Sheikh Nasser."
However, FF told the BBC the prince would need to "consider the risk of investigation, arrest and prosecution when he is travelling outside Bahrain".
Last year the prince posted a video of himself, running with the Household Cavalry in Hyde Park, on Instagram, whereupon Bahraini human rights groups handed a dossier of new evidence to police.
The new dossier was given to the Metropolitan police's SO15 war crimes team at Scotland Yard, which confirmed it was looking at the evidence. However, no arrest was made. It apparently included a statement from a witness willing to give evidence in a UK criminal court, but no prosecution followed.
International concern about human rights abuses in Bahrain have been growing since February 2011, when the Arab Spring spread to the capital, Manama. Over 100 people have been killed and thousands arrested by the Bahraini authorities. Public demonstrations have been banned in the capital and Amnesty International has said that prisoners have been burned with cigarettes and given electric shocks.
However, cooperation between Britain and Bahrain has been growing: The UK is in the process of building a permanent naval base in the kingdom and has licensed £45 million worth of arms since the Arab Spring uprising began. Yesterday the British ambassador in Manama offered a statement in support of Bahrain's reform process. However, three weeks ago the kingdom was added to the Foreign Office's list of "human rights priority countries".
The news that Prince Nasser is attending the Royal Windsor Horse Show has angered human rights protesters.
Andrew Smith of Campaign Against Arms Trade said: "It has been more than five years since the pro-democracy protests began in Bahrain, and yet the UK government is still providing an uncritical political and military support for the regime.
"The current partnership may benefit the Bahraini authorities and the arms manufacturers, but it is only helping to entrench the status quo. There are very serious allegations of torture against Prince Nasser and the regime; he should be put on trial, not given the red carpet treatment."
Sayed Ahmed Alwadaei, director of advocacy at the Bahrain Institute for Rights and Democracy, said: "The UK is destroying its credibility on Bahrain when it stands shoulder-to-shoulder with Bahrain's repressive monarchy, celebrating the false end of reforms and hosting an alleged torturer at the Royal Windsor, while rights defenders and democracy advocates continue to serve unjust prison terms."
BuzzFeed News attempted to contact the Bahraini embassy in London this afternoon, but calls went unanswered.