Ed Sheeran's dad ''didn't believe'' he'd been cut with a sword by Princess Beatrice.

The 'Castle on the Hill' hitmaker was reportedly struck by the 28-year-old royal as she was pretending to 'knight' fellow musician James Blunt at a party at the Royal Lodge in Windsor in November, but he admits he has told few people about what really happened.

He said: ''I have no idea how it came out as there weren't a lot of people there that night.

'For two weeks after, I had a huge gash on my face and would tell people I fell and then suddenly, the story came out...

''I remember telling my dad about it and he didn't believe me and said, 'No, what really happened?' ''

But Ed insisted he can't be drawn on the details of the ''alleged story'' as he fears a backlash from the royal family.

He insisted to talk show host Graham Norton: ''I can't talk about it. I don't know what will happen if I do!''

Despite being reluctant to discuss the incident, the 25-year-old star recently admitted he was left ''completely covered in blood'' from the cut.

He said: ''I got hit in the face and I was like, alright, OK, and then started carrying on and then I looked down at my shirt and it was just completely covered in blood.

''And everyone was kind of gaping open-mouthed at me. What have I got a nosebleed or something? What's happened?''

But the experience hasn't put the 'Shape of You' musician off hanging out with royalty as he recently said he'd ''have a lot of fun'' with Prince Harry.

Asked to name candidates for an imaginary squad, Ed said: ''Harry Windsor, because I don't really know him that well but I think I'd have a lot of fun with him.''