Mr Ridley said he has never spotted a big cat himself.
He set up a website, Surrey Panther Watch, for people to log sightings, saying his goal is to “conclusively prove that big cats are living wild in Surrey”.
He said: “Since the 1960s, Surrey residents have described encounters with large, cat-like beasts, some black, some tan.
“Many sightings report a labrador-sized black cat, similar in appearance to a panther or puma, as well as sandy-coloured pumas and lynx.”
Waterers Park in Knaphill has been the location of a number of recent sightings.