NEW YORK: Criminal gangs across the world are pursuing a new, lucrative and almost untraceable commodity: Lego.

Sets of the brightly-coloured plastic bricks can sell for thousands of pounds on online trading sites, prompting thieves to target toy shops from America to Australia.

The trend came to light this month when US police revealed back-to-back cases in New York state and Arizona worth almost $300,000 (Dh1.1 million).

Caleb Raff, who runs the Brick Hutt Lego shop in Santa Rosa, California, said he knew of several similar thefts near his store.

Mr Raff, who earlier this year sold a single piece for $15,000 — the Platinum Avohkii Mask of Light, made especially by Lego for a competition — said criminals seemed to be getting wind of the collectability of some sets.

“If you look at other makes — Kenner, Hasbro, Fisher Price, those have always been collectable,” he said. “With Lego, it’s a new trend and if you know what to get then there’s value.”

Lego’s popularity is surging after years of crisis saw the Danish family business turned over to new management. Tie-ins with films, such as the Star Wars and Harry Potter series, have helped it connect with a new generation of children and quadruple its revenues in less than a decade.

Expensive specialist kits include Tower Bridge or the Ewok village, from Return of the Jedi, which sell for £150 (Dh915). Prices can rise much higher for unopened, discontinued lines, such as a 2,899-piece Statue of Liberty, released in 2000, which now sells for £6,000.

That rise in prices has created a lucrative online trade — and a black market.

Police in Phoenix, Arizona, spent four months investigating thefts from toy shops, monitoring CCTV footage before identifying four suspects. When officers made their move last week, they found 18 pallets of Lego sets stored in the garage of one of the suspect’s homes, worth more than $200,000.

That case was followed by another in Long Island, New York. A 53-year-old woman was arrested after allegedly taking $60,000 of Lego sets from a storage facility and trying to sell them on eBay, the Nassau County police department said in a statement.

Detectives in Australia are looking for a gang behind a number of thefts in two states, where angle grinders were used to break into stores. Two years ago, a Silicon Valley executive was caught sticking fake bar codes on collectable Lego sets, buying them at large discounts before making a profit by selling them on eBay.

Officers said Thomas Langenbach’s thefts, for which he was later sentenced to a month in prison, included a $279 Millennium Falcon kit from Star Wars that he had bought for $49. In mint condition, some versions of the spacecraft, captained by the character Han Solo in the films, can sell for more than £6,000.

When police searched Langenbach’s home near San Francisco they found hundreds of unopened kits, as well as dozens of creations he had built himself.