The late Princess Diana had a "huge effect" on the world, according to son Prince Harry.

Prince Harry

Prince Harry

The 32-year-old royal - who is the youngest child of the late royal who tragically died in 1997 and her ex-husband Prince Charles - was amazed by the reaction to his late mother's death, which made him realise the impact his parent had on "so many people".

Speaking in a clip of a new 90-minute BBC documentary about Diana, which has yet to be named, obtained by the Express Online, Harry said: "When she died, there was such an outpour of emotion and love which was quite ... which was shocking.

"It was beautiful at the same time, and it was amazing, now looking back at it, it was amazing that our mother had such a huge effect on so many people."

The programme will see Harry and his older brother Prince William, 34, open up about their parent and their emotions following her death 20 years ago, but the fame-haired hunk doesn't think it will ever be easy for the royal brothers to openly talk about Diana.

Harry - who is currently dating 'Suits' actress Meghan Markle - continued: "When you're that young and something like that happens to you, I think it's lodged in here, there, wherever - in your heart, in your head and it stays there for a very, very long time.

"I think it's never going to be easy for the two of us to talk about our mother, but 20 years on seems like a good time to remind people of the difference that she made not just to the royal family but also to the world."