Reports from Papua New Guinea say 42 inmates from Baisu Jail in Western Highlands Province have escaped.
The newspaper, The National, reports that this followed a confrontation between prisoners and warders over Monday's death of an ill prisoner on remand.
Prisoners reportedly asked warders to transfer the ill man to hospital but a lack of vehicles and fuel meant it couldn't be done.
The inmates cut through cell block bars and perimeter security fences under cover of darkness to escape.
The police commissioner, Gari Baki, says some of the prisoners are hardcore criminals, raising the risk of increased lawlessness.