Penalty in lieu of prosecution: administrative levy tied to the tax that would have been payable, barring criminal action. The registering authority may, after giving the purchaser a reasonable opportunity of being heard, impose by written order a penalty not exceeding one and a half times the tax that would have been levied on the sale to him; imposition of such a penalty precludes prosecution for the same facts. The penalty is to be collected by the Government in the prescribed manner, with the State for collection determined by where the purchaser obtained prescribed forms or where he should have registered.