A regular heath user believes he has solved the mystery of the UFO sightings above the park – but new fears have been raised over the danger of the true culprits.

Stephen Greensted said that this time last year, he came across a man launching eight Chinese lanterns from a football pitch in the park.

Last week a woman reported the puzzling sight of “six orange balls of light” hovering above Hampstead Heath to the UK UFO Sightings website.

Mr Greensted said they are likely to be Chinese lanterns that can float well above the trees and cast an orange glow.

He explained: “I was on my evening run and I was wondering what all these bright lights in the sky were, and then I saw a chap on the football pitch with his two sons, lighting Chinese lanterns.

“Whilst I was standing there, they launched about eight.”

“If people have seen six of these balls of ‘orange light,’ that’s entirely credible.

“It was about the same time last year, so I wonder if it’s part of a Chinese New Year celebration.”

For now, alien invasions may be nothing to fear, but concern has been raised over the candle-lit lanterns causing fires. Mr Greensted explained: “The lanterns usually float above the trees, but if they’re not let off from high enough, they could come as low as houses.”