I hope, you kept the pounds to yourself.
Why would a company with a german name and legal construction (a GmbH is a Germany type of limited) work from London?
The only reaction besides ignoring such a mail is to reply with "Deduct the expenses and send the rest to me."
I have heard of a case in Germany involving a spanish lottery, where the poor guy spent more than 40000€ and never got anything.
Should something happen to me I would go straight to the prosecutors.