Mike Sewell told the breakfast show that he saw a "disc-shaped" object hovering above a field as he drove to work at 4.15am.
"I was driving east cross country, about 15-20 miles from StanstedAirport, 4.15 in the morning, and I saw this big bright light in the sky descending towards the road and as it got close it then banked left and as it banked to the left it went across the countryside," he said.
"I could see underneath and it wasn't an aeroplane and it wasn't a helicopter. It had several lights flashing all around it and underneath there were at least two large panel lights, like soft white lights, and it just sat or it circled a certain area over the fields."
Speaking on the radio, UFO expert Timothy Good said he believed the flying object, which he said was "clearly not a conventional aircraft of any type", could have been from outer space.
"It might well be extraterrestrial, it might well be one of ours," he said. "I know for a fact that top secret aircraft and spacecraft have been flown by the United States military and by the British military for quite some time now. As Ben Rich said, who developed the stealth aircraft, back in 1993 in the presence of two friends of mine, we now have the technology to go to the stars."
Asked by presenter Nicky Campbell how that was possible, Mr Good said: "The study of alien crafts which have been recovered and by liaising with actual aliens who have helped us develop this technology."
Last month, a local family claim they had a close encounter after seeing three mysterious glowing orbs floating in the night sky above Sawbridgeworth, as reported in the OBSERVER.
