Cat Neelan

This new Brexit party is a departure from Nigel Farage's old machine.

Gone is UKIP's signature purple and gold, replaced with an icy cool blue.

But this party is not just cosmetically different.

It's set up as a business.

A business with a mystery at the heart of it.

This is Dr Sam Power, one of the UK's leading experts in political finance.

By the end of its first year, the Brexit party has raised millions.

In fact, a lot more than you would expect for a party of its size or age.

But if you wanted to know who has given them all that money, you'd struggle to find out.

There's very little public information.

This mystery is a useful place to start because it's also the starting point for reform and some of the key people involved then are playing important roles now.

Word is getting out that Nigel Farage has a new project.

This is Ben Habib.

He's a businessman who, until this point, has been a supporter of and donor to the Conservative Party.

So he signs up.

If you're setting up a party, Ben Habib is exactly the kind of person you might want to have around.

He's a wealthy businessman with experience of working in politics already.

But the Brexit party isn't after his money, which is weird because establishing a brand new party isn't cheap.

That's my producer, Poppy Bullard, speaking to Ben Habib.

So why wouldn't a small party be on the hunt for as many donors as it could find?