Toyworld was robbed twice within ten days and the thieves also took store's sliding glass door and CCTV hard drives. A number of other stores have also been targeted.
"It has been a spate of robberies through the smaller toyshops over the last six months or so. And they're only targeting LEGO," Toyworld owner Werner Baumann told 3AW radio. "Over the last 12 months it has become one of the hottest toy properties in Australia."
The thieves mostly took LEGO Technic and City brands.
"There's a lot of other things they could probably steal that would be worth a lot more ... but they're only targeting LEGO," Baumann said.
According to Detective Ian Porter of Victoria Police, the complicated and specific nature of the thefts suggests than "an organized syndicate" could be involved.
"On the second occasion the store manager hasn't been able to replace the CCTV in time, so they knew what they were doing," Porter told ABC.net.au. "We believe it's an organized group of people who've done a bit of planning and homework."