Are we really still going with the "personal security" story? I thought he had pivoted a couple of times to other, not necessarily more credible, stories.
Have you got evidence for otherwise? He does appear to have 3-4 security people, driver etc.
I guess technically he never said it wasn't for security. Apparently the 5m was an unconditional gift for campaigning for brexit, and how he had spent the money was “not the public’s business”.
https://www.bbc.co.uk/news/articles/c072prlxlddo
https://www.channel4.com/news/factcheck/factcheck-the-latest...
He can make that case to the investigating committee. If Farage finds that inconvenient then, well, the easiest way for him to avoid such scrutiny in future is to declare any large amounts of money he receives. Not that difficult, and surely in the public interest to do so.
Personal security would come under that.
I mean you may not agree, but it's an arguable case.