The vehicle was believed to have been making a slow backing manoeuvre.
The company said a full accident and emergency procedure was instigated by the company. Staff were comforting Mr Hyde's wife, who was not travelling with him at the time.
Southern Discoveries chief executive Tim Hunter said all of its staff were "deeply shocked and saddened" by the incident. "Our deepest sympathies go to his family and friends."
The company was supporting staff involved and all Queenstown operations had been suspended until further notice.
A police serious crash investigation has been launched. Southern Discoveries is working closely with police and the serious crash unit investigating the incident.