A complaint about an election expenses return filed by John Banks has been passed to police.
The Labour Party has complained to the Auckland Council that Mr Bank's return after his unsuccessful mayoral campaign in 2010 failed to declare a $15,000 donation by casino operator SkyCity.
The council's returning officer says he is legally obliged to pass to police any complaint filed in writing.
Bruce Thomas says while Mr Bank's return does not list a donation from SkyCity, it does list a $15,000 anonymous donation.
Sky City says it made identical donations to campaigns by Mr Banks and by Auckland mayor Len Brown.
Mr Brown declared the donation.
John Banks is now leader of the ACT Party.
