A Christchurch inmate's tax rort from inside prison was so successful he applied to become a tax agent.
His success also attracted the attention of a gang, which demanded a slice of the action.
Carl Milson Petterson is serving an 11-year jail term at Christchurch Men's Prison.
Before that term was imposed, he was in jail serving a term for earlier offending.
He has effectively been in prison since 2008.
While serving the earlier sentence he began helping other inmates with legitimate tax-return claims and obtained them legal refunds.
That led to him making a series of fraudulent claims in other names, totalling about $50,000.
He was paid for his work in cash or goods such as tobacco, and he applied to become a tax agent.
Word of his ability in the taxation field spread through the prison, and gang members put pressure on him to provide his methods to make more false claims.
After the frauds were discovered, Petterson appeared in the Christchurch District Court and pleaded guilty to 24 charges of obtaining funds or causing a loss by deception.
Inland Revenue has accepted that getting any of the money back from Petterson is impossible, so no reparation order was made at his sentencing today.
Judge David Saunders imposed an additional one-year jail term on the 11-year sentence Petterson is serving.
He said Petterson would need "substantial intervention" by way of treatment at a high-intensity special treatment unit.
He noted Petterson was working well within the prison.
- The Press