A self-confessed UFO sceptic believes he saw "something not of this planet" when he stepped out of his Wrose home yesterday.
James Bacon had been checking a flight radar website and popped outside to see if a flight from Helsinki to Manchester was passing over his house at about 9.15am.
Instead, a white object that was darting to and fro caught his eye.
"It was absolutely amazing," said the 59-year-old, of Haslam Grove. "At first I dismissed it as a bird. But it was the speed and the way it was flying that was a concern to me.
"The way it was moving around, it wasn't a plane or a helicopter - it was darting back and forth. It was shooting around.
"It was like a beautiful speed - my head was going from left to right."
Mr Bacon, who used to work as a security guard at Leeds Bradford Airport, said he was transfixed by the object by three minutes before it disappeared behind a cloud and never reappeared.
Both the Ministry of Defence and the Civil Aviation Authority said they had received no other reports of strange sightings in the area.