Christmas is off to a flying start here, thanks to Gary Rodger, who alerted me to the following lines in Robin Askwith's Wikipedia entry:
"Recently several internet sites - including the IMDB - claimed Askwith had played the lead in Oh No, Its Derek Anus, a 1972 LWT sitcom. However it has since emerged that this was an internet prank/hoax and no such TV show exists, the IMDB no longer carries a listing for Derek Anus."
The trouble is that I now want this show to be real. It couldn't be worse than Bottle Boys.