New Zealand police have dismissed a possible sighting of missing British girl Madeleine McCann, more than two years after a report was passed on to Portuguese authorities.

The reported sighting came from a checkout operator at a shop in the southern city of Dunedin in December 2007, five months after Madeleine disappeared from her family's holiday apartment in Portugal.

Police said they had identified the girl and her family captured by the store's security camera and ruled out any link to Madeleine, Inspector Dave Campbell said.

On Wednesday police defended their lack of action at the time of the possible sighting, saying they were never asked to follow up after passing on the report to Portuguese police.

Details of the incident emerged Wednesday after British newspapers reported the contents of a dossier from Portuguese police, containing a series of sightings from around the world that were never investigated.