Staff at Christchurch Men's Prison have caught a woman allegedly using a young boy to courier drugs into the prison.
Prison manager John Roper says the woman was seen hiding something in the child's jersey after she came through the jail's entrance on Saturday.
Staff say they detained the woman and four children and found a package containing what appeared to to be cannabis oil, pills and methamphetamine.
The woman was allowed to arrange child care for the children before she was arrested.
Mr Roper says this is the third significant drug seizure at Christchurch Men's Prison in the past month.