The New Zealand forest adventure park where a man fell to his death from a high wire had indicated that it planned to register under tough new adventure tourism regulations.

However, like other high rope adventure companies, Tree Adventures was not required to pass a safety audit until mid-2014, considerably later than operators of river boarding, mountaineering and canyoning businesses.

Clifford Brabet, 57, died after plummeting 14 metres from the highest course in the Woodhill park near Auckland about on Sunday.

His wife, daughter and more than 100 others watched on in horror as Mr Brabet, an IT professional from Titirangi, fell to the ground.

The park will be closed while police and the Ministry of Business, Innovation and Employment investigate.

Tree Adventures is one of dozens of New Zealand adventure companies that will be expected to meet strict new safety guidelines introduced after British tourist Emily Jordan's river boarding death in 2008.

By November 2014, it will be illegal to operate an adventure tourism business without being audited and registered.

However, operators have different deadlines for their safety audit, with high ropes course businesses not required start an audit until the end of the year. They have six months to pass it.

Deadlines are considerably sooner for bridge swinging, canyoning, mountaineering and river boarding, followed by abseiling and rock climbing.

A ministry spokesman confirmed Tree Adventures was among companies that had already notified its intent to register under the regulations.

Both police and witnesses are puzzled as to how the accident happened given that harnesses and metal clips called carabiners are used to secure climbers to metal wires above them.