Lego larceny may be on the rise.

French police have been investigating an international ring of toy thieves with a particular affinity for the colorful, interlocking bricks, according to a recent report from The Guardian .

In this case, three suspects were caught taking boxes of Legos from a toy shop near Paris, with the goal of selling them in Poland, according to Le Parisien .

And it's not just Europe. Lego robberies have happened in the United States as well. Last month, a man in Oregon was arrested after local police suspected he stole $7,500 worth of Lego toy sets.

There's a lot of money in Legos. Lego sets come out in limited editions and they soon become collectors' items.

There might even be a whole black market for the bricks, Lego specialist Gerben van IJken tells Scott Simon on Weekend Edition.

"Well, that's very difficult to prove that there's a black market. However, there is an enormous amount of collectors out there who are missing out on certain sets right now and are willing to pay a lot of money for these sets," he says.

Van IJken is an auctioneer at an auction website for collectibles. He says the most valuable and sought-after sets are those in their original packaging, not opened yet.

For example — Lego Café Corner, a set released in 2007 for about $150, can nowadays run up to $3,000 if kept in its original condition, van IJken says.

Other sets routinely fetch thousands of dollars in online marketplaces. Some sellers are asking for more than $3,500 for an unopened set of the Lego Millennium Falcon.

Just like almost everything else in the world, the pandemic could be a driving force behind this phenomenon.

"Especially during the lockdown period, as we are in right now — it's still extremely popular," van IJken adds. "And Lego sales are still extremely high, not only in the Lego Company itself but on our platform too. We saw a 100% rise in sales over the past year."

Peter Breslow and Kitty Eisele produced and edited the audio version of this story.

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