Police say they received a handful of election-related complaints, including an alleged bylaw breach in the Christchurch suburb of Sydenham.
Strict rules mean all election advertising and signs must be taken down and no campaigning or advertising is permitted on election day.
This rule also applies to media who cannot report any political stories that could influence voters.
A police spokesperson said a report logged this afternoon alleged a bylaw breach in Sydenham.
The complainant said people were carrying party billboards and knocking on doors in the suburb.
The police said they were not found.
The Electoral Commission said more people have registered to vote in today's election than at the last one in 2011.
A final total is yet to be released but the latest figures show 3,096,240 people have registered for the country's 51st general election, at least 20,000 more than three years ago.