Litres of chemicals that could be turned into homebaked heroin have been stolen from the University of Canterbury.
Its chemistry department was burgled overnight on Sunday, but the theft was not reported to the police until Wednesday while the university carried out its own internal investigation.
Detective Sergeant Richard Quested said the products may have been taken to make illegal drugs.
Mr Quested said police would be making further enquiries this weekend and were asking for anybody with information to call them.
Police were also trying to work out how someone stole the chemicals without having to break in.
Mr Quested said there were no signs of a break-in so the culprit might have access to the building.
"That's a possibility that we're looking at but we have to keep an open mind that it could have been someone else, could have been an opportunistic thing or yes, as you say, it could have been someone who had access to the lab."
Mr Quested said anyone who found discarded chemical containers or suspicious chemicals in the area should contact the police.
The university said it took security seriously and had moved some chemicals and compounds to a more secure location.