Cash, methamphetamine and drug paraphernalia have been confiscated from two visitors to Auckland South Corrections Facility in Wiri after a standard car park check.
The Department of Corrections says 19 grams of methamphetamine, $11,000 in cash, a butane burner, scales, several shotgun shells and alcohol was discovered in the car.
The search was part of a routine search of visitors, performed by detector dogs and Serco staff.
Police were advised and removed the visitors from the site.
A 29-year-old man and 24-year-old woman are now facing multiple charges including possession of methamphetamine for supply and unlawfully carrying a firearm or weapon, NZME reports.
Corrections staff says they're glad to have caught the drugs before they entered the prison.
"This is a great example of Corrections, Serco and police working together to stop the distribution of drugs in the community and in prisons," chief custodial officer Neil Beales said.
"Meth wrecks people's lives, and is often linked to a person's criminal offending.
"In a prison environment, prisoners who are affected by drugs can behave violently, and compromise the safety of staff and other prisoners."