A leopard seal has returned to Auckland's Westhaven Marina after a year travelling around the upper North Island.

Photo: Supplied / Giverny Forbes

Last summer Owha was spotted in the marina and elsewhere in the Waitematā Harbour.

This year she's returned with a companion, a smaller seal Niwa has named Novy.

Both seals are being tracked by Niwa scientists.

Photo: Supplied / Don McGrath

The species has been known to be aggressive towards humans so people are being warned to keep away from the seals and keep dogs on a lead.