A St John spokesman said emergency services were alerted to the incident on Malaghans Rd, under Coronet Peak about 11am.
It appeared a paraglider carrying a pilot and a paying passenger had crashed on a steep slope.
In a statement, police said two people were ''being extracted'', one with moderate injuries, the other with minor injuries.
A New Zealand Herald photographer at the scene said the reserve parachute had "definitely deployed".
"So something's happened that he's needed to deploy the reserve parachute,'' he said.
Skytrek said the Civil Aviation Authority had been informed and the company was co-operating with relevant authorities and local police. The company had temporarily suspended its commercial operations.
- additional reporting NZ Herald