So they got away with it, but what do they do now? How do you shift a stash of cash so huge it needs a lorry to move it?
"They have a big problem," said Jeffrey Robinson, an expert on money laundering. "When you have a large sum of stolen money, you want it to be in the form of a blip travelling across computer screens in the Bahamas or northern Cyprus. You don't want it in a heavy, cumbersome stack of notes."
Robinson, author of The Laundrymen, suggested that if it were a matter of wanting to get away with one or two million pounds, the best bet would be to put it in a suitcase and head for South America or eastern Europe, hoping to slip past customs.
Gangs behind the former iron curtain are particularly adept at concealing large amounts of illicit money, because their economies are largely cash-based, he says.
There are also ways of depositing cash in offshore accounts and then disguising it by moving it electronically.
But laundering ?22 million in cash is much more difficult. And it is that much harder in this case because of the type of notes.
Police confirmed yesterday that all the notes were issued by Northern Ireland banks.
Officially, such notes are not even legal tender in the province, never mind further afield.
They are accepted in Northern Ireland by custom rather than law. But many shopkeepers in the rest of Britain are unfamiliar with them and refuse to take them.
Robinson said: "These guys have a big problem.
Moving this money abroad is not going to be an option. And if they try to spend it in Northern Ireland, bang, they're going to be caught.
"When you pig out, you get a stomachache. That's what they have done. And they are going to have one very big stomachache."