The princess says she is being held captive in a barricaded villa in video message filmed in a bathroom and obtained by the BBC in February.
The UN has said it is "very concerned" for Dubai's Sheikha Latifa, two months after having asked the United Arab Emirates for proof that the royal is still alive.
In February, the United Nations Human Rights Office asked for evidence about the daughter of Dubai ruler Sheikh Mohammed bin Rashid al Maktoum after the BBC broadcast a video shot by Latifa saying she feared for her life and that she is being held against her will in a barricaded villa.
Sheikh Mohammed is the vice president and prime minister of the UAE, of which Dubai is one of the seven emirates.
His 35-year-old daughter has not been seen in public since a foiled attempt to escape from the emirate in March 2018.
The Office of the UN High Commissioner for Human Rights spoke to the UAE's diplomatic mission in Geneva in a bid to obtain proof of life.
"We are very concerned," spokesperson Marta Hurtado told reporters in Geneva.
"We haven't got any proof of life and we would like one, and one that is clear, compelling evidence that she is alive.
"Our first concern, of course, is to be sure of that: that she is still alive."
Last March, a London High Court judge said he accepted as proved a series of allegations made by the Dubai ruler's former wife, Princess Haya, in a legal battle, including that the sheikh had ordered the abduction of his daughter Latifa.
The sheikh's lawyers rejected the allegations.
"I am a hostage and this villa has been converted into a jail," Latifa, 35, said in the video published by the BBC on Tuesday.
"All the windows are barred shut, I can't open any window." She said she was making the video in the bathroom of the villa, the only room she could lock herself into.