Marine experts have revealed that sightings of a deadly sea snake in Northland - aren't as rare as you might think

Residents came across a venomous yellow-bellied sea snake at Woolleys Bay, north of Whangarei, over the weekend - and another in Tokerau Beach, even further north, more than a week ago.

DOC expert Clinton Duffy says they get swept down in ocean currents every year - probably from the north Tasman Sea.

He says people believe that we don't have snakes in New Zealand - but we have three of them - and they're all sea snakes.