Police are following several leads following the movement of machinery at the Forsyth Barr Stadium building site in Dunedin at the weekend.
Early on Sunday, someone moved a crane attached to a truss stretched between the north and south stands.
The crane was moved about 20m over a high voltage power cable and through a fence.
Other machinery was also moved.
Senior Sergeant Mel Aitken said the matter had been referred to the CIB, which was investigating.
