Princess Latifa, the captive daughter of Dubai's ruler, has appealed to UK police to re-investigate the kidnap of her older sister from a Cambridge street more than 20 years ago.
In a letter Latifa tells Cambridgeshire police this could help free Princess Shamsa, who was captured on the orders of their father.
Shamsa, who was just 18 then and is now 39, has not been seen in public since.
The government of Dubai has not responded to requests for comment.
A High Court judge ruled in 2019, that Sheikh Mohammed bin Rashid al Maktoum had abducted both daughters and held them against their will.
shocking videos Latifa had secretly recorded on a phone she had been given, in which she described how she was being held "hostage" by her father following a failed escape attempt in 2018. The UN has since asked the United Arab Emirates for proof that Latifa is alive.