The Solicitor-General is taking over the private prosecution of ACT party leader John Banks for electoral fraud.
Michael Heron is taking up the case from retired accountant Graham McCready after an Auckland District Court judge last week ruled that Mr Banks must stand trial on a charge of making a false electoral return.
Mr Heron has written a letter to Mr Banks' lawyer saying he is assuming responsibility and has asked for all relevant documents to be forwarded to the Crown Law office.
The prosecution says donations towards Mr Banks' 2010 Auckland mayoral bid from casino operator SkyCity and internet businessman Kim Dotcom, were signed off as anonymous when Mr Banks knew who had made them.
Mr McCready said on Friday it is a victory not just for himself, but for the public that a citizen can take a private prosecution and gain the full weight of the Crown's support.
Meanwhile, Mr Banks' lawyer David Jones says they applied to the High Court on Friday for a judicial review and the first hearing on that will be on 31 October.