He said the approved KiwiSaver funds were no different to others that the commissioner routinely acted on.
"Why should she benefit at the expense of the country with this particular withdrawal?"
The police commissioner's lawyers also told the Court of Appeal that there were no barriers within the text of section 25 when it came to recovering funds like this.
The money has already been removed from her KiwiSaver account but is currently in a public trust bank account which Harrison cannot access.
Lawyer for Harrison, Nathan Bourke, said the money was not and has not been in her control.
He argued that police should not have been able to restrain the funds as they were not in her possession.
Justices David Goddard, Patricia Courtney and Christine French are presiding over the case and have reserved their decision.
The judges will also discuss whether more evidence will be needed for the decision to be made.
Harrison, also known as Joanne Sharp, was deported to the UK in 2019 after serving most of her sentence.
Before she was employed by the ministry, Harrison worked at Tower Insurance — where she also committed fraud — and then at the Far North District Council, where she held a senior HR role from June 2007 to October 2008.
A case led by the Serious Fraud Office found she had defrauded the ministry over a period spanning about 10 years while she was employed as a general manager.