DOHA, Jan. 17 (Xinhua) -- A controversial member of Qatar's royal family has flown to Kuwait after his alleged detention by the United Arab Emirates (UAE), local media reported Wednesday.

"My father is on his plane to Kuwait with his two daughters," said Sheikh Ali bin Abdullah al Thani, the son of Sheikh Abdullah, who emerged as a negotiator and one of the most prominent figures speaking out against Qatar in the ongoing diplomatic dispute between Qatar and other Gulf nations.

When asked about his father's possibility of returning to Doha, Sheikh Ali did not give a definite answer.

"After arriving in Kuwait and checking his health, he will decide to return to Qatar or travel abroad for treatment," he said.

Sheikh Ali also said his father's health was "not stable" as he was suffering from heart disease and diabetes.

On Sunday, Sheikh Abdullah posted a video saying he was detained in the UAE.

"I am afraid something could happen to me that will be blamed on Qatar," he said.

The UAE, however, denied that Sheikh Abdullah was being held against his will and said he was "free to leave."

Last June, Saudi Arabia, the UAE, Bahrain and Egypt severed diplomatic, trade and transport links to gas-rich Qatar, accusing it of supporting terrorism and establishing close ties with Iran against Arab interests, which Doha has repeatedly denied.