Is the mystery of the Calvin UFO in Scotland finally solved?

Simon Holland, a former BBC producer, believes he has found an explanation for the famous 1990 UFO photo.

On August 4, 1990, two young chefs were walking through the Cairngorms National Park, near Perth, when they noticed a strange diamond-shaped object in the sky.

Terrified, the two men hid behind bushes to watch the mysterious ship.

Soon after, they heard the sound of an approaching Royal Air Force plane. The plane appears to change course and circles the UFO for a while before resuming its original path.

Wanting to take a picture, one of the men points the camera at the sky and takes several pictures. After a few seconds, the object flew into the sky and disappeared.

What people saw that day remained a mystery for more than 20 years, but former BBC producer Simon Holland believes he has found the answer, and it's not about aliens.

His own investigation revealed that the object could have been part of a classified radar protection system involving a diamond-shaped aircraft accompanied by jet aircraft.

"The Ministry of Defense previously stated that on August 4, 1990, no "known" Harriers flew in Perthshire," the report says.

"It turned out to be a big clue as to who it was. I found out that the only other British Harriers were from BAE Systems, a defense company. They used their Harriers as multi-roll protection test platforms, testing BAE's advanced technologies.

I dug further and discovered that Marconi Advanced Materials, based at BAE headquarters in Wharton, Lancashire, was probably working on an advanced "invisible" coating material for the US Air Force."