It happened at a business premises on William Street in Hull at about 2.30am on Monday, November 11.
Three men jumped out of a van and stole just under £4,000 worth of Lego toys before driving away.
Police have now released CCTV images of the van used.
It is described as a "distinctive" looking van with a coloured rear door and an unusual roof rack.
The registration number of the vehicle isn’t known.
Humberside Police are appealing to the public for help in finding the van and urging anyone who has been sold Lego models to contact them quoting reference 16/123858/19.