A photo of Princess Diana and rock legend David Bowie smiling side by side at a concert in London seemed to have been hidden for decades.But why did the royal family want to keep it a secret for all these years?

The year was 1987. Princess Diana was 25 years old and attending a charity concert at Wembley Stadium, where the legendary David Bowie would be performing that evening.

O’Regan now tells the Daily Mail that Diana was suggested a photo together, and she wondered if Bowie would agree to it.

Bowie agreed, and the picture was taken.However, the next day, the palace issued a request: the photo should not be published.It wasn’t that the picture was somehow inappropriate. It wasn’t that Bowie was in it. It was about who was with Diana.The princess had arrived at the concert with Major James Hewitt. There were rumors (that were later found to be true) about an affair between the two at the time, and the palace didn’t want to add any more water to the rumor mill. Hewitt tried to keep a low profile and stayed out of the photographers’ lenses. “No one knew who he was so I had no reason to picture him and the word wasn’t out yet about their relationship,” O’Regan said.

So he decided not to publish the picture himself – and he still stands by his decision.