Latifa Al Maktoum's cousin Marcus Essabri is said to have recently met the missing princess in Iceland.
On Monday, a picture was published on Instagram where the cousins can be seen together on the island.
Marcus Essabri described the reunion as very emotional, according to the campaign website FreeLatifa.
- It was reassuring to see her so happy, prosperous and focused, the cousin said according to the website.
The princess has previously appeared in several photos on Sioned Taylor's Instagram account.
Taylor also published the latest photo from Iceland.
The princess has not yet commented
After the meeting, FreeLatifa has decided that the most appropriate step is to close the campaign.
The main purpose of the activity was to ensure that the princess could live her life the way she wanted.
The meeting in Iceland is seen as a sign that they have reached there.
"We have clearly come a long way towards achieving that goal in the last three years, with bodies such as the UN now monitoring Latifa's current and future well-being," writes FreeLatifa.
It is still unclear to what extent the princess, who has not spoken publicly, is acting of her own free will, according to the BBC.
David Haigh, co-founder of the campaign, says Latifa's situation is "the best she's been in when it comes to freedom in two decades".
However, he points out that everyone should continue to monitor the situation closely.
Unsuccessful escape attempt
Princess Latifa tried to escape from Dubai in February 2018. It failed.
In videos that the princess secretly recorded, she describes her capture and captivity after she was forced to return to the emirate.
According to the videos, the princess was kept locked in a villa surrounded by police with barred windows and doors.
The princess said she feared for her life.
The Dubai royal family has said in a statement that the information is incorrect.
The family has not commented on the latest photo of the cousins in Iceland.