A contractor working at Waikeria Prison has been injured after falling into an empty water tank.
Prison Director Jim Watson said the contractor was working to replace the bladder of an empty water tank at the prison this afternoon when he fell into the tank.
He said emergency services were on site and working to assess the man's injuries, remove him from the tank and take him to hospital.
There was no issue with water supply to the prison, Watson said.
Two firefighting crews from Te Awamutu were called to the incident about 4.30pm.
Contractors "made an opening" in the empty water tower and local firefighters helped extract the man.
The man was flown to Waikato Hospital by helicopter.
WorkSafe will be notified.