The government said there was a technical inconsistency in migration regulations and how they apply to the Bridging (Removal Pending) - BVR - visas issued to the group of people released from indefinite immigration detention.
The inconsistency dates back to 2013 when the visa was created, and rendered the BVR visa issued to the NZYQ group invalid.
149 people were released in the grouping and 148 are known to have been on visas that were invalid due to this inconsistency in law. One person had a valid visa.
The 148 people with invalid visas have had their visas re-issued, with strict conditions attached.