Amateur photographer Ray Gilbert reckons he caught more than one flying object on camera when a Dakota aeroplane completed a flypast over Grantham Carnival on Saturday.
Mr Gilbert, of Montrose Close, Grantham, discovered a mysterious dot on one of the digital pictures he took of the flypast.
He said the dot has a flat top and a red rim around it only visible when he zooms in on it on his computer.
Ray, who claims to have seen a UFO last year when he was travelling to Lincoln, said: "I took more photos of the flypast but this is the only one with a dot on it.
"When I saw it a chill went down my back and everyone I've told says I should inform the Ministry of Defence. I know it's a UFO and I'm wondering if anyone else saw the same thing."
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