Why would you keep that type of cash in bitcoin? Anyone with half a brain would at least put that kind of money in a savings account to get interest. I think it's a hoax.
The only reason I can think of is if you are running a business and want to dodge taxes. It'd also be a good way to hide money from say, selling drugs.
On a side note, I believe it is still illegal to make your own currency in the US. I don't see the government spending too many man hours solving this. If the claim is real, I think that person will never see that cash again.