A Chinese couple have been stopped at the border after being found carrying items deadly to our bird population.

The pair, who'd travelled here from Shanghai for the birth of their grandchild, were caught with a large quantity of edible bird nests at Auckland airport.

Ministry of Primary Industries spokesman Craig Hughes says the item could have carried avian diseases with the potential to wipe out our native and commercial bird populations.

The couple were refused entry and flew back to Shanghai on Tuesday night.