Penelope, Lady Diana and Mossie are arrested by a Customs Officer when they return to England with 20 million pounds provided by the genies. That exact amount has just gone missing from the Royal Mint.
Penelope, Miss Mossop and Lady Diana are arrested by an officer and caught with 20 million pounds when they are returned to England. The genies provided them with all the money. They were arrested because that amount of money was stolen from the Royal Mint.