The Corrections Department says it has strengthened systems on entering prisons to make it harder for contraband to be smuggled in.
Former Rimutaka Prison guard Johan Clarke, 42, was on Thursday jailed for two years and three months by the High Court in Wellington on six charges of corruption
He admitting taking a variety of items into the prison, including methamphetamine, fast food and a cellphone.
He is the first New Zealand prison guard to be charged with corruption.
Corrections Department chief executive Ray Smith says six people are employed to investigate such allegations.
Other security improvements have also been made, he says, including the x-ray screening of everyone entering prisons, and the use of drug detection dogs.
