The Duke of York will be the keynote speaker at a conference in London this Friday celebrating Bahrain as a place of religious freedom and tolerance of divergent opinions. Speaking during a visit to Bahrain last month, he said: "I believe that what's happening in Bahrain is a source of hope for many people in the world and a source of pride for Bahrainis."

This is very strange, as the island kingdom of Bahrain has a proven record of jailing and torturing protesters demanding democratic rights for the Shia majority, an estimated 60 per cent of Bahraini citizens, from the Sunni al-Khalifa monarchy. In its annual report on human rights, the US State Department identifies many abuses, the most serious of which include "citizens' inability to change their government peacefully; arrest and detention of protesters on vague charges, in some cases leading to their torture in detention". It draws attention to the fact that "discrimination [has] continued against the Shia population".

None of this should be too surprising. In March 2011, the government in Bahrain crushed the Bahraini version of the Arab Spring, treating protesters and anybody associated with them, such as doctors who treated injured demonstrators, with extreme brutality. The Bahrain independent commission of inquiry, set up by the Bahraini government itself, described at least 18 different techniques used to mistreat or torture detainees including electric shocks, beating on the soles of the feet with rubber hoses, sleep deprivation and threats of rape. More than 30 Shia mosques, religious meeting places and holy sites were bulldozed on the pretext that they had no planning permission.

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Prince Andrew has long and controversial experience of Bahrain which he used to visit frequently as special representative for trade and investment. In 2010, an excoriating account of Prince Andrew's behaviour was published in the Daily Mail by Simon Wilson, British embassy deputy chief of mission in Bahrain from 2001 to 2005, who wrote that the prince was known to the British diplomatic community as HBH: His Buffoon Highness.

Mr Wilson tells stories of Prince Andrew's arrogance, rudeness and self-regard. Among other things, the prince insisted that his valet should carry a six-foot ironing board, even in the five-star hotels in which Price Andrew stayed, so that his trousers should be ironed just right.

Prince Andrew loved being among the absolute monarchs of the Gulf and was so awed by their wealth that he treated them with embarrassing sycophancy, says Mr Wilson, adding that "the thank-you letters he sent to his hosts after one visit to Bahrain – referring to 'my little plane parked next to your stunning jet' – made for cringe-making reading". The prince was officially in Bahrain to promote British business, but Mr Wilson says that the British embassy was astonished when, in discussing the sale of British-made Hawk aircraft, he advised the Bahrainis not to buy it (but lease it). Mr Wilson attributes the prince's boorishness to an inferiority complex, believing "his attitude usually drew attention to the fact that he was out of his depth".

Out of his depth then and out of his depth now, except that now the stakes are more important. Prince Andrew is no longer trade representative, having resigned in 2011, but he is helping in a PR campaign to enable the Bahraini government to regain international respectability while, at the same time, increasing repression at home. Further emphasising his cosy relations with British royalty, Bahrain's King Hamad bin Isa al-Khalifa is expected to attend the Royal Windsor Horse Show next Sunday to watch the Kingdom of Bahrain Trophy.

The meeting Prince Andrew is opening is called "This is Bahrain!" and is arranged by the Bahrain Federation of Expatriate Associations. Betsy B Mathieson, the BFEA's general secretary, told me that the meeting "is to celebrate our cultural diversity, freedom of religion and the fact that multiculturalism not only survives but thrives in Bahrain at a time when many countries are faced with growing xenophobia and racial and religious tensions". Unfortunately, the reality of life for most Bahrainis is one of growing violence and sectarianism. The UN special rapporteur on torture, Juan Mendez, has expressed his "deep disappointment" over Bahrain's decision to postpone his visit indefinitely. He expressed his "compassion with the people of Bahrain who were expecting my visit, and in particular, victims of torture and ill-treatment and their families".

Jawad Fairooz, a Bahraini former MP, says that "recently the attack on the Shia has increased dramatically". In exile in London, Mr Fairooz is one of 31 Shia Bahrainis arbitrarily stripped of their nationality 18 months ago. He says that, so far, the government has not fulfilled its promise to rebuild 38 bulldozed Shia mosques and religious meeting places and is demanding that their sites be changed "though some of them have been in the same locations for 200 years". He says that Shia activists seeking civil rights are demonised as agents of Iran.

Bahrain is on the verge of a deeper religious conflict between Shia and Sunni. A senior Shia cleric, Sheikh Hussain al-Najati, one of the 31 stripped of Bahraini citizenship, was given 48 hours to leave the country last month. Last month, Ayatollah Sheikh Issa Qassim, the most prominent Shia spiritual leader on the island, accused the Bahraini state of declaring "open war on the Shia sect".

Ayatollah Qassim's call for continued non-violent opposition may not be heeded by all. The number of people in jail in Bahrain is not known but the opposition gives a figure of 3,500. "After three years of non-violence people are getting radicalised," says Ala'a Shehabi, an activist in exile. "They have effectively removed all the non-violent leaders who used to lead street protests." She believes that the vacuum is being filled by radical groups.

I asked Ms Mathieson at the BFEA how she reconciled her claims about the spirit of tolerance and respect supposedly prevalent in Bahrain with the 31 Shia activists being stripped of citizenship. She replied: "The kingdom of Bahrain has the sovereign right to put national security before the human rights of the individual just as USA, UK and other countries." She absolutely denies opposition suspicions that the BFEA event in London is in any way sponsored or paid for by the government of Bahrain and says its message is "one of peace, love, harmony and unity".

Bahrainis may have difficulty contradicting this since the interior minister threatened legal action against those who make allegations of torture. As for Prince Andrew, if he does turn up on Friday, he will play a small but ignoble role in concealing the tragedy of Bahrain.