Former athlete Mary Decker has revealed she thinks about the controversial collision with Zola Budd at the 1984 Olympics “every day”.

The pair have taken part in a documentary about the 3,000 metres final called The Fall in which they discuss one of the most memorable moments in Olympic history.

There had been controversy in the build-up to the race with Budd, who was born in South Africa, adopting British nationality in order to avoid the international sporting boycott of her country because of apartheid.

American Decker was widely expected to win gold at her home Olympics in Los Angeles, but fell and was injured after they made contact.

Budd, 18, faded in the race to finish seventh, to jeers from the US crowd.

She was found not to have deliberately tripped her rival and has since claimed she has never seen footage of the race.

Budd, now aged 50 and who famously ran bare-footed, said: “I knew making this film would be opening up the black box in my mind which I haven’t opened since that day. I thought it was time.”

Decker, 57, added: “I still think about that race every day. Making this film has been cathartic.”

Sky commissioning editor for factual and documentaries James Quinn said: “The Fall is gripping, deeply moving and beautifully made, revealing the astonishing story behind one of the most memorable moments in modern Olympic history.”

The Fall will be shown on Sky Atlantic on Friday July 29 at 9pm.