Corrections is warning negligent staff will face action, if they're connected to a string of suspected murders in shared cells at Mt Eden prison

There's been three deaths involving double bunking at Mt Eden Prison, in just over 12 months.

Rob Fitzpatrick's death is one and he was allegedly beaten to death by a man who was accused of attacking someone near a Mangere bus stop.

Corrections Custodial Services Commissioner Leigh Marsh says he's having a very close look at the information available to staff when both men arrived at the jail.

He says there are currently no employment investigations underway, but this could change following ongoing reviews and coronial inquests.