Dr David Clarke of Sheffield Hallam uni
He's a lecturer in journalism with a PhD in folklore. Worthy stuff, I'm sure, but when he speaks on the subject of UFOs, I think it would be more accurate to refer to him as just "Dr David Clarke". It's not like he holds his academic position at Sheffield on the strength of his research in any field related to UFOs. I don't suppose the science faculty at Sheffield really appreciates the link.
On the other hand, he's entitled to a hobby and (now that the man at the MoD has retired) he probably *is* Britain's foremost expert on UFOs. As you may have noticed, Britain doesn't actually *need* much expertise in UFOlogy so it doesn't get funded much.