Crimes such as house burglaries and theft have decreased while fraud and identity theft have risen, as criminals match their skills with improving technology, a criminologists says.

Sophisticated home and vehicle security systems, combined with increased reliance on credit-based as opposed to cash-based commerce, have seen traditional property crimes dramatically decrease over the past 20 years, University of Canterbury criminologist Professor Greg Newbold said.

"This drop has been offset, however, by rises in crimes like simple fraud, identity theft and credit card fraud.

"As these crimes have grown in frequency and sophistication, however, so have detection and policing methods improved."


An Auditor-General's review in 2008, prompted a multi-agency intelligence unit, which had seen reported benefit frauds triple since that time, Prof Newbold said.

"Last year, a record $23.4 million in benefit fraud was detected. There has also been a greater reliance on private security organisations and computer technology in the monitoring and detection of fraud.

"So the increases in reported frauds are a consequence of two processes: a real rise in levels of fraud within the community, and better detection methods."

Prof Newbold said although reported fraud rose dramatically after 2008 it appeared to have stabilised over the last two years with little further change expected in the next 12 months.

Although benefit fraud accounted for $23.4 million in the last year, such sums were "trifling" compared to the scale of frauds perpetrated by the corporate sector, he said.

"In recent years, corporate crooks have been convicted of crimes involving frauds involving sums as high as $88 million.

"Another huge area of fraud involves the tax system. It is estimated that up to $5 billion of dollars in taxes goes unpaid every year as a result of clever tax avoidance and evasion schemes," Prof Newbold said.