There have been 42 convictions to date as a result of failure to complete forms for the 2018 Census, Statistics Minister James Shaw has revealed.

Mr Shaw provided the information in response to written parliamentary questions from National MP Lawrence Yule.

Mr Yule asked how many fines and prosecutions were carried out after the 2006, 2013 and 2018 censuses as a result of citizens not completing their census forms.

Mr Shaw said 60 cases were approved for prosecution after the 2018 Census, but "only 42 convictions have been made to date".

For the 2013 Census, 99 cases were approved for prosecution with 46 convictions resulting. For the 2006 Census, 73 cases were approved for prosecution with 43 convictions resulting.

Mr Shaw says that in all cases for the 2018 Census, prosecutions were only lodged against individuals who are alleged to have repeatedly and wilfully refused to complete their forms despite direct offers of assistance from Statistics New Zealand staff.