A prison guard has been charged with smuggling drugs to Mongrel Mob inmates.

The 45-year-old was arrested in Auckland today and appeared in Manukau District Court charged with corruption after allegedly smuggling contraband into Tongariro Rangipo Prison, near Turangi.

The Herald revealed last year the prison guard lost his job in 2009 after he was allegedly caught supplying cannabis to the "Cedar One" unit in Rangipo Prison after being bribed by gang associates.

The officer in charge of the investigation, Detective Sergeant Neale Saunders from Turangi Police, said the corruption charge carries a potential prison sentence of up to seven years.

"This is a serious charge, and as such, is required to be signed off by the Solicitor General. We received notification that this had been processed late yesterday, and the man was arrested in Auckland this morning."

Detective Sergeant Saunders says the man appeared in the Manukau District Court today. He received bail and is to appear in the Taupo District Court on May 25, 2011.

Corrections chief Ray Smith said the department employed about 8000 staff.

"The former officer was dismissed from employment in December 2009. Corrections referred the matter to police and worked closely with them on the investigation," he said.

"We set very high standards for our staff and the vast majority of them approach their role with professionalism and integrity. When these high standards are called into question, it is highly disappointing."