It appears the poor chap contracted and died of Covid.............

https://uk.yahoo.com/news/jethro-dead-102957885.html

He nearly killed me a few years ago. I bought a cassette of his from a motorway services in the 90s. Listening to him whilst in the fast Lane of the M6 nearly had me off the road. It was his story of him and Denzil going to see Michael Jackson at the NEC and ending up at a spiritualist convention.