Claims a Waikato prison is on a 22-hour ongoing lockdown, are being rejected by the Department of Corrections.
Prisoner advocacy group No Pride in Prisons has made the allegation about Spring Hill prison - saying it's because guards can't control inmate violence.
But Chief custodial officer, Neil Beales, said Spring Hill follows a normal regime, just like any other jail around the country.
"The normal regime operating at Springhill at the moment is basically an eight to five regime, where prisoners are unlocked in the morning, around the eight o'clock time."
Beales said the only place where prisoners are kept locked up longer is in what's called a management unit.