Mail from prisoners will now be blocked if it promotes hostility to groups of people

The Corrections Amendment Bill passed its third reading last night.

Changes were drafted after mail from the alleged Christchurch gunman was published online.

Corrections Minister Kelvin Davis says the move enhances the safety of prisoners, victims and staff.

Further changes include making it an offence for a prisoner to tattoo another person... and allowing prisons to use imaging technology to detect contraband.