Newshub can reveal allegations of prison officers being paid thousands of dollars by the family members of prisoners to smuggle in tobacco.
The claims involve a small number of guards working at the Serco-run South Auckland Correctional Facility, which is also known as Wiri Prison, and the previously Serco-managed Mt Eden Correctional Facility.
A family member of an inmate who's been in both facilities has told Labour's Kelvin Davis about arranging meetings with guards or a guard's family, and paying them $500 to smuggle in two packets of tobacco.
Newshub has obtained a copy of the phone call between Mr Davis and the informant, which lasts more than 30 minutes and details the dealings with both male and female officers.
The person says they've done deals on three occasions, with two being done behind a south Auckland Caltex station, and the other via internet banking.
"I just have to ring up and they give me a time to meet them, and it's always been at the Caltex by the prison. It's always $500 a time plus two packets of tobacco," the person says in the recording.
"At Serco at Mt Eden, I was paying a warden there to get smokes in. Just smokes though, but it's still $500 a pop. That's how much the screws, I mean the wardens, are asking for."
Mr Davis says it's not the first time he's been told of officers being paid off to smuggle in cigarettes, and if the claims are correct, it's corruption.
"These things are being swept under the carpet," he says.
"It's a case of see no evil, hear no evil. If they don't want to look for it they won't find it.
"One thing it goes to show is that sometimes the criminals are on the other side of the bars. If this is true, this is a level of corruption that needs to be investigated."
In a statement to Newshub, the Department of Corrections said the allegations are "very serious" and invites Mr Davis to provide the information he has to either Corrections or police for investigation.
"Contractors and staff are all subject to random and targeted searches on entry to a prison, and anyone found to have facilitated the entry of unauthorised items will be held to account," a spokesperson said.
Mr Davis is calling for Corrections Minister Judith Collins to launch an investigation into the claims.
Ms Collins urges the Labour MP to pass the allegations on to Corrections.
"Any information about contraband in prisons needs to be passed directly to Corrections who will undertake the appropriate investigations," she says.
"I can share this information with the minister if she wants me to do her job," says Mr Davis.
"Judith Collins needs to do her job. Why is it that people come to me instead of going to her and getting things done through her office?"
Paul Henry has invited Ms Collins to appear on the show tomorrow morning.