(FORTUNE Magazine) – At 31 years of age, Columbia Law grad Brad Meltzer has already produced the best-selling thrillers The First Counsel, The 10th Justice, and his most recent, The Millionaires (Warner Books, $25.95). Meltzer spends months immersing himself in the worlds inhabited by his subjects, in this latest case the shrouded realm of banking and money laundering. He recently took time out from his book tour to talk to FORTUNE about hiding money--and why it sometimes takes dirty diapers to do it.

Q: So the book makes it sound like it's pretty easy to get into money laundering.

A: I spent two years talking to the government's top financial investigators, and one of the things I took away from everything they taught me is how easy it is to hide your money. It is pathetically easy.

Q: Can you really find a money launderer in your local Yellow Pages?

A: They're called the stutterers. That's a code name for the people who are in the first alphabetical listings of every telephone book--for instance, AAAAAAAA Attorneys. I called one up once, and I said, "Hi, my name is Brad Meltzer, and I'm looking for a lawyer." He said, "You've got one." I said, "Great, what's your name?" He said, "What do you need?" I said, "What's your name?" He said, "What do you need?" And I realized that this is where Tony Soprano gets his attorney.

Q: They also advertise in those in-flight magazines?

A: You'll invariably see an ad that reads something to the effect of "Sick of the IRS? Take your money offshore." These are ads for people who will hide your money. Period. People always think of this as some kind of dastardly deed that is done only by villains in bad movies--in reality this is happening every single day.

Q: Were you surprised by how easy it is to dig up private information about people?

A: I was blown away by it. I hired a private investigator to put me under investigation as part of my research. She took "Brad Meltzer," and in a minute she had my Social Security number. Within ten minutes, she had my life. The No. 1 trick is Dumpster-diving. She'll say, Okay, this guy buys expensive honey-roasted turkey. He's not buying the cheap stuff, which means he has a little bit of disposable income. Now she sees you're a man, but you have a Tampax wrapper in there. Now she knows you have a girlfriend--but there's only one wrapper, which means she's not sleeping over. She finds a People magazine in there; it has a subscription label. Now we have the girlfriend's address--let's go talk to her. You can't shred that stuff.

Q: So if you're under investigation, you should start eating lots of...liverwurst?

A: Yeah, exactly. Or put a couple of dirty diapers in there.