Watch: 'It's very rare' – suspected 19th century shipwreck exposed on Auckland's rugged Muriwai Beach

Shifting sands at Muriwai Beach have revealed a remarkably intact 17-metre shipwreck.

Archaeologists, however, are being hampered by souvenir hunters, and the Defence Force has concerns too. Source: 1 NEWS

Made of kauri and pohutukawa, archaeologists such as Auckland Council's Robert Brassey say it's likely to be a 19th century schooner.

"It's just the sort of thing that would have traded between the west coast harbours – Onehunga, Raglan, Kaipara and further north," Mr Brassey said.

High tides uncovered the vessel at the weekend but the ship's already been looted for deck timber, annoying Heritage New Zealand's Greg Walter.

"Although it's a wreck it's relatively complete and together at this point, what we can see of it and for people to come along to just help themselves to the parts of it just makes our job that much harder."

He and Mr Brassey are trying to determine the ship's age, if it pre-dates 1900 it's automatically protected under heritage laws, making scavenging illegal.

Since 1 NEWS visited yesterday someone has taken to the timbers with a chainsaw, a spokesman for the NZDF said. Police are investigating.

Anyone caught doing so face fines of up to $60,000.