The United Nations said it was still waiting for convincing proof that Sheikha Latifa, the daughter of Dubai's ruler, was alive after two pictures emerged purportedly showing her in public.
In February, the UN human rights office asked for evidence about Dubai's ruler Sheikh Mohammed bin Rashid Al-Maktoum's daughter after the BBC broadcast a video shot by Ms Latifa saying she was being held captive and feared for her life.
Sheikh Mohammed is the vice president and prime minister of the United Arab Emirates, 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.
Two pictures were published on an unverified Instagram account this week, purporting to show Ms Latifa in a restaurant and in a shopping centre in Dubai.
AFP is unable to verify the photos or when they were taken.
The Office of the UN High Commissioner for Human Rights told reporters in Geneva that the UAE had declined comment on the Instagram pictures.
"The government of the United Arab Emirates has been engaging with us on both diplomatic and government levels on a number of occasions over recent weeks and that engagement continues," UN rights office spokesman Rupert Colville said.
"They have told us they will provide convincing proof of life in the case of Latifa. So we're essentially awaiting their next step in this respect and will carefully examine any proposal that emerges.
"In terms of the photographs that emerged in the last few days, we don't really have any comment to make on those at this point.
"We haven't received them ourselves and have not been able to examine them."
In a statement in February, Dubai's royal family insisted that Latifa was being "cared for at home".
"We are hopeful she will return to public life at the appropriate time," it said.