A dolphin has been decapitated on a beach north of Kaikoura

The Department of Conservation is calling for more information after a Dusky dolphin was found by a member of the public, without its head.

Kaikoura Marine Reserves Ranger Zac Penman says it's thought to have washed up naturally before someone took its head.

He says it's illegal to injure, kill, or take parts of a marine mammal and this horrific act is unacceptable.