The 22-year-old son of Mongrel Mob Aotearoa president, Joseph 'Junior' Wiringi, was on remand in Christchurch Men's Prison when he made his bid for freedom.
The Star has been told the prisoner was unshackled by escort staff but the Department of Corrections would not comment on security arrangements.
"A review into the circumstances of the incident will be carried out. As the review is ongoing, we are limited in the amount of information we can provide," said Christchurch Men's Prison director Jo Harrex.
"Staff pursued the prisoner but were unable to locate him. Police were informed and were actively searching for him."
Once apprehended, Wiringi was likely to be charged with escaping custody, a charge which carries a maximum sentence of five years imprisonment.
Police would only add they were "assisting in locating a person".
A Southern Cross Healthcare spokesperson said no staff were injured during the incident.