"The British police claim there are millions of sexual abusers."

Curiously, this claim from London police is unsourced and appears in a document which is all about asking the government for more money. It also makes up a tiny part of it and is an "estimate".

Have you considered the possibility that they're exaggerating to try to get more funding?

Instead of vague and intangible estimates, a more relevant statistic might be how many cases they have to process, how many are likely to lead to a judicial outcome, and whether they feel those are adequately resourced. After all, it's a funding pitch document.

They even take the time to complain about the media criticizing them, presumably this refers to articles calling them racist. Or when controversial "emergency" covid powers were misused by a cop to rape and kill a woman.