State Services Commissioner Peter Hughes will also look at other government departments as he looks into a Inland Revenue poll that included a question about the political leanings of taxpayers.
Hughes has also written to public sector chief executives to remind them about the importance of political neutrality.
Hughes was asked by State Services Minister Chris Hipkins to look into why a government department polled the public on a number of political questions and to provide an assurance that the principle of political neutrality was understood.
It came after Stuff revealed the Inland Revenue had asked questions about whether people sit to the right or the left of the political spectrum in a poll about globalisation and fairness in the tax system.
Hughes said today he would look into other government departments as well as the Inland Revenue matter.
He had also issued a clear reminder to chief executives about the importance of political neutrality to remove any doubt.
"I have told them that it is never acceptable for a government agency to seek or collect information on the political leanings or party affiliations of citizens," Hughes said in a statement.
"Political neutrality is a fundamental principle of the Public Service – one that cannot be compromised for other interests. New Zealand's public service has an international reputation for political neutrality and it is vital we uphold those standards."
In his letter he told chief executives that perception could be just as damaging to public trust and confidence as reality.
"The environment in which political neutrality plays out is increasingly complicated and presents new challenges," he said.
Hughes said he would report back to Hipkins in about six weeks.