Where they find non-recyclable materials in the bins which are less than 10 per cent of the total volume, the resident receives an orange warning tag and the bin is collected.
However if the wrong items are more than 10 per cent of the total volume, or if there are red flag items such as nappies, hazardous waste, liquid or wire, the bin is red tagged and won't be collected.
A letter explaining the reasons for non-collection is also put in the resident's mailbox.
Auckland Council's Waste Solutions GM Ian Stupple says the aim of the bin inspectors is to help residents get better at recycling.
"Inspectors have audited over 100,000 bins and so far just over 2200 bins have been red tagged," says Stupple.
"When we revisited areas where there were a large number of red tagged bins we noticed a marked improvement so it's clear this approach produces results."
Stupple says the council is happy to help people understand what can and can't be recycled but residents who continue to offend, or grossly contaminate their bin, will not have the bin emptied.