That makes sense. I was thinking masters might be tested even at the amateur level but I guess that's rare even at the high levels of competition.
The race organiser does not pay for the testing directly. British Cycling takes a small levy for every rider taking part in a race and I imagine this goes towards paying for the random testing.
The UK anti-doping website has a list of all current and historical bans for drug test rule violations covering a wide range of sports:
https://www.ukad.org.uk/anti-doping-rule-violations/current-...