UPDATED 7.17pm: An inmate at Otago Prison has died from a suspected cardiac arrest.

Staff at the Otago Corrections Facility found the 29-year-old man unresponsive this morning.

Prison Director Jack Harrison says he was given medical attention but died at the scene.

The death's been referred tot he Coroner, although police and the Prison Inspectorate are investigating.

It's the second death at the prison in the last two months, a man also died in November last year.