The Orakei boardwalk in east Auckland was badly damaged by a suspicious fire overnight.
Detectives from Glenn Innes police went to the scene between Orakei Rd and Manapu St, Meadowbank, about 7.30am.
Police said a number of planks had to be removed from the boardwalk so that firefighters could extinguish the blaze.
It was not safe for public use in this state and Auckland Council had been notified to close the structure.
Anyone with information was urged to contact Glen Innes CIB on (09) 524 1921 or Crimestoppers anonymously on 0800 555 111.
