Did you try to contact HSBC through a number other than the one they give you and ask about this? I would.
Did you ever enter the lottery? (How can you win if you never enter?)
Did they ask you to send money? (Why would they do that? If they needed the tax money, then they should have withheld it or you would need to pay the government directly when you received your winnings.)
So what do you think? Are you being scammed?
Regards
Tim
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