Senior Sergeant Dylan Earle of Dannevirke Police said Mr Reid had just started his shift with a forestry crew of seven fellow workers.
"The worker was cutting a tree which became caught up, before clearing itself and continuing to fall, crushing the man beneath it," Mr Earle said.
Mr Reid was working with another person who was about 100m away in a loader.
The victim was "an experienced forestry worker," who had begun working with the crew four months ago, Mr Earle said.
Emergency services, including St John ambulance and the Pongaroa Volunteer Fire Brigade were called, but the man died at the scene.
Investigators from Occupational Safety and Health are conducting their own investigation.
Tararua police have referred the incident to the coroner.
CTU president Helen Kelly said the death showed the industry needed a "rigorous review into its employment practices".
"We welcome the work the Government is doing in health and safety including the Independent Taskforce Review but something is seriously wrong in this particular industry and a special investigation is required," she said.
Ms Kelly said the industry was controlled by a few big forest owners who largely contracted out cutting work to small employers that were forced to compete on price to win work. She said this practice led to long working hours, low pay, higher risks and extreme working conditions.
Glen Mackie, senior policy analyst of the Forestry Owners Association, said he believed health and safety practices were improving in the industry.
"We're not happy when any serious incident occurs. We have an active health and safety programme. We are a high-risk hazardous industry, which has to be recognised, but we are improving year-on-year," he said.
"We have a goal of zero serious-harm incidents and we are working towards that goal."
Forestry fatalities:
January, 2010: Port Underwood, Marlborough, Forestry accident.
January, 2010: Forest Block Tokoroa, crushing injuries.
February, 2010: Paeroa, crushed by bulldozer.
September, 2010: Whenuakite, crushing.
December, 2010: Wharerata Forest, crushing.
February, 2011: Marlborough, struck by tree branch.
August, 2011: Dunedin, hit by tree.
February, 2012: Boy aged 5, Motueka, killed by log.
March, 2012: Atiamuri, hit by hauler rope.
April, 2012: Wanganui, crushed by tree.
June, 2012: Gisborne, killed by log.
June, 2012: Opotiki, falling branch.
November, 2012: Pongaora, crushed by falling tree.
