Sheikh claims he is being held against his will in the UAE

Saudi King Salman, left, walks with Qatari Sheikh Abdullah bin Ali Al Thani, right, last August in Tangiers, Morocco. Photo / AP

A controversial member of Qatar's royal family claimed he was being held against his will in the UAE, eight months into a crisis between the Gulf states.

Sheikh Abdullah bin Ali Al-Thani, a little-known royal, emerged as a key figure in the dispute between the Gulf states in the weeks after Riyadh and Abu Dhabi cut ties with Doha.

He is seen by some as a potential challenger to the Qatari leadership.

A video circulating online, also broadcast by Qatar-based Al-Jazeera television, shows the sheikh seated in an armchair warning that he was "afraid something could happen to me that will be blamed on Qatar".

"I am now in Abu Dhabi, where I was a guest of (UAE crown prince) Sheikh Mohammed" bin Zayed al-Nahyan, said Sheikh Abdullah, "That is no longer the case. I am now detained. I want to make clear that the people of Qatar are innocent."

"Sheikh Mohammed bears full responsibility for anything that happens to me."

The video could not be immediately authenticated, while Emirati officials were not immediately available for comment.

Saudi Arabia, the UAE, Egypt and Bahrain severed diplomatic and trade ties with Qatar in June over allegations Doha supported Islamist extremists and had close ties to regional rival Iran. Doha denies the accusations.

In response to the video, Qatar's Foreign Ministry spokeswoman, Lulwa al-Khater, said in a statement that Doha was monitoring the situation.

"The state of Qatar observes the situation closely, and due to the total severance of ties with the UAE it is difficult to clearly establish the circumstances surrounding the situation," she said.

"Despite that, the State of Qatar principally stands with the protection of rights for every individual and affirms the entitlement of his family to pursue all legal means for the protection of his rights."