Queen Elizabeth II's 90th birthday festivities could not have gone ahead without the “generous support” of Middle East rulers and a British arms manufacturer, Middle East Eye can reveal.

Buckingham Palace already faced fierce criticism for seating the queen next to the King of Bahrain at her 90th birthday gala last week, but human rights groups have reacted with fury after it emerged that the four-day celebrations at Windsor Castle were made possible by support from Bahrain's king, the Sultan of Oman, the Republic of Azerbaijan and arms manufacturer BAE Systems, as well as other blue-chip companies including Jaguar Land Rover, Waitrose, Rolex, BT and BP.

The event feted the queen’s reign and like other royal events was funded by corporate sponsorship, but Human Rights Watch, anti-arms trade campaigners and Bahraini activists have condemned the roles played by the Gulf governments and BAE Systems.

All three countries have poor human rights records and histories of clamping down on freedom of speech, but campaigners have focused their attention on Bahrain, which violently suppressed unrest during the 2011 Arab Spring and is facing international criticism for ongoing violations including the detention of human rights defender Zainab al-Khawaja after she tore up a picture of the Gulf state’s monarch.

Britain recently signed defence agreements with Bahrain and Oman to secure naval facilities as part of a military return to the region east of Suez, while BAE Systems also sponsored receptions celebrating the queen’s birthday at British embassies in Bahrain and Qatar.

Sayed Ahmed Alwadaei, director of advocacy at the Bahrain Institute for Rights and Democracy, told MEE: "Zainab al-Khawaja languishes in prison with her infant son for daring to express herself and tearing the Bahraini dictator's photograph. It is outrageous to see him shoulder-to-shoulder with the queen, while the Bahraini people's call for democracy is met with arrest and torture."

Nicholas McGeehan, a researcher at Human Rights Watch, said: “The revelation that Bahrain supported the celebrations suggests that either the royal family don’t know about the abuses going in in Bahrain, or that they don’t particularly care.”

The four-day birthday gala was a celebration of the queen’s reign and her involvement with foreign affairs and the military. On each evening, 900 horses took part, with as many as 1,500 guests. The first night was broadcast on ITV, with 7.5 million viewers watching performances by Shirley Bassey, James Blunt, Gary Barlow, Beverley Knight and Kylie Minogue. A spokesperson for Buckingham Palace said the queen attended in a “private capacity”.

“I’m not in a position to talk about how the event was financed,” the spokesperson added, when asked if taxpayer funding had been used.

The event’s official commemorative book includes a note of thanks to the rulers of Bahrain and Oman. It said: “This celebration could not have been possible without the support of generous individuals and organisations.” It went on to list the two Gulf states as well as British and international companies, including BAE Systems.

The British arms-maker has long faced criticism for selling weapons to governments with questionable human rights records in the Middle East. Most recently it was chastised over its dealings with Saudi Arabia, which is at war in Yemen and has been accused by a UN panel of conducting “widespread and systematic” attacks on civilian targets.

Andrew Smith, a spokesman for Campaign Against Arms Trade, said: "Royalists and republicans may not always see eye to eye, but one thing everyone can surely agree on is that the queen's birthday should not be used as a propaganda vehicle for dictatorships and a business opportunity for arms companies.”

Smith added: “The government may talk about the importance of human rights, but the fact that the queen's sponsors included three human rights-abusing regimes and Europe's biggest arms company is a sign of the doublespeak and hypocrisy that is at the heart of UK foreign policy."

A spokesperson for BAE Systems said: "Along with many other companies, we were approached by the organisers to ask if we would be a sponsor of the event. We were extremely proud to support the event to commemorate the landmark birthday of the country’s longest-serving monarch."

In a statement, the organisers of the event said the celebrations "could not have been done without the support received from a number of major international companies, including principle partner Jaguar Land Rover, and many other household names."

It added that the Kingdom of Bahrain had been an "enthusiastic partner" of the equine elements of the celebrations, while the Royal Cavalry of the Sultanate of Oman as well as Azerbaijan dancers and horses "wowed the nightly sell-out crowd".