A prison inspector has rebuked jailers for advising inmates to relieve themselves on vehicle floors.
One inmate said he was told to urinate through a drain hole while he was handcuffed in a vehicle moving from Wellington to Auckland.
The Herald on Sunday has obtained emails showing Inspector David Morrison's concern about inmate Brendon Forrest's complaints.
Forrest, in jail for arson, threatening to kill and perjury, is a repeat complainer - but Morrison found his concerns deserved investigation.
"Staff have been advising prisoners on long-haul escorts to urinate on their cell floors," Morrison wrote on April 16.