Authorities are bemused by a rare case of dumpster diving for cheese - then sold on the black market in South Waikato

NZ Food Safety has issued warnings after Over The Moon brand cheese products appear to have been taken from Putaruru Landfill - and re-sold in the town at well below retail price.

MPI is working with Police on the matter.

Deputy-director general Vincent Arbuckle says he's never encountered such a thing.

He says a landfill usually isn't a place where people go looking for food to resell, so it's very unusual and also very distressing for the company.