As the fallout continues from Phillip Smith's escape to Brazil, reform campaigners say other prisoners will be caught in the crossfire.

A Herald on Sunday investigation has revealed an Auckland Prison officer is being investigated for allegedly supplying a mobile phone and helping Smith secure a passport.

Prison Reform Society president Barry Hart says it's not the first time prison officers have been accused of playing favourites.

He says each time such allegations are raised, other prisoners lose out.

Barry Hart says prisoners who aren't involved will be affected by a general tightening of rules, including reduced parole privileges.