ACT leader John Banks joins a growing list of current and former MPs who have fallen foul of the law.
Most recently, former justice ministers Sir Douglas Graham and Bill Jeffries, who represented National and Labour respectively, were found guilty of making false statements as directors of the failed company Lombard Finance.
The pair were sentenced to home detention last year, but on appeal this was reduced last month to community service.
Former National minister Roger McClay, who served from 1981 till 1996, was convicted in 2010 of defrauding charities World Vision and Keep New Zealand Beautiful, as well as Parliamentary Service, of almost $25,000.
He was sentenced to community service.
Former Labour minister David Butcher was convicted in 1999 of three counts of claiming air fares under a scheme for former MPs. He was fined $10,000 and ordered to pay reparation.
Former Labour MP Taito Phillip Field was jailed in 2009 after being found guilty of 11 charges of bribery and corruption and 15 of attempting to obstruct or pervert the course of justice.
The charges related to using Thai tradesmen to work on his properties in Samoa and New Zealand in return for giving them immigration assistance.
He was sentenced to six years in prison.
Former ACT MP Donna Awatere-Huata was jailed in 2005 for stealing money from the Pipi Foundation which she founded to help underprivileged children.
Awatere-Huata, who was expelled from the ACT caucus in 2003 when the allegations were raised, was sentenced to almost three years in jail. She served part of her sentence on home detention. Her husband Wi Huata was also jailed as a result of the offending.
Another former ACT MP, lawyer David Garrett, resigned from Parliament in 2010 after it was revealed he had some 26 years earlier fraudulently obtained a passport in the name of a dead infant.
Further back, John Kirk, son of former prime minister Norman Kirk, fled New Zealand while still an MP in 1984 owing more than $280,000.
He went to the United States where he was imprisoned before being sent back to New Zealand and charged under the Insolvency Act. He served four months in prison.
In 2011, former NZ First MP Gilbert Myles was convicted of obstructing the course of justice for hiding evidence but was acquitted on fraud charges. He was sentenced to community detention and community work
Patrick Webb, an outspoken critic of conscription during World War 1, was jailed for sedition while still an MP in 1918.
Of the current crop, Labour MP Ruth Dyson was convicted of drink-driving in 2000 while her colleague Trevor Mallard pleaded guilty to fighting in a public place in 2007 after an altercation with National MP Tau Henare. Like Banks’ case, Mallard’s was initiated by private citizen Graham McCready.
Will Judith Collins' resignation hurt National at the polls?Related story: Judith Collins resigns, says she's a victim