https://www.bbc.com/news/uk-politics-48337499
This is what I meant when I said 'anonymous donors yes please'.
The Brexit Party has raised a lot of money in a short time and doesn't verify the names of people donating less than 500 pounds via PayPal as other parties do, which is not an offence on itself unless the same donor donates more than 500 pounds. Problem is that unless you verify the names you have no way of knowing, so a rich foreign businessman or hostile foreign power could have paid for this and there is no way of knowing. The Brexit Party hasn't broken any laws with this but let's say does things a bit differently.
Farage says it's all above board and it's a smear campaign, but remember that Leave.eu (which is basically Farage, Banks et al) denied all wrongdoing regarding campaign finance for the referendum, called it a smear, then in the end quietly admitted breaking the law.
Oh yes and now Farage wants to dismantle the Electoral Commission, so nothing suspicious at all.