[saulr]

> the fact that Post Office Ltd has inherited the ability to prosecute crimes committed against itself

Any private citizen or business in the UK has a right to prosecute crimes. It just costs a lot of money, so you can imagine how it's used (spoiler: large companies/wealthy individuals against poor people).

[mnw21cam]

The Crown Prosecution Service also has the power to take over a case that is being prosecuted privately, and if they decide to take no further action on it, then the person/company that was doing the private prosecution no longer can.

[JdeBP]

You should have read the more-on-which first. (-: