Under the Electoral Act, it is a criminal offence to distribute or broadcast any statement likely to influence voters over which candidate, party or referendum option they should or shouldn't pick on election day. Those found in breach can face a fine of up to $10,000.
By 8.45pm yesterday, the Electoral Commission had not received any complaints about the billboard. It only takes action when complaints are laid.
Former league star Ridge has long been a known face on the celebrity circuit. He made gossip headlines when his marriage to Sally Ridge broke up and he dated Nicky Watson, his ex-wife's best friend. He now has a son, London, with former TrueBliss singer Carly Binding.
Meanwhile, in Dunedin, a resident laid a complaint with the Electoral Commission over a handful of people wearing sloganed T-shirts in a polling booth.
The complainant, who wishes to remain anonymous, saw scrutineers in a booth wearing red Service and Food Workers Union T-shirts with a Labour Party rosette.
The T-shirts were branded SFWU on the sleeve and had the union's Fairness at Work slogan on the front, the complainant said.
The complainant called the commission and was told the shirts fell into a "grey area".
"I agreed. It wasn't a Labour Party slogan but it was intended to sway a vote to Labour," the complainant said. "It may have been a genuine idea but if I heard of instances where other T-shirts had been worn at other polling booths then I certainly think there would be a case to answer."
Other voters had asked the booth manager whether the T-shirts breached the law, the complainant said.
The Electoral Commission spokeswoman confirmed there had been a complaint and said the scrutineers agreed not to display the slogan once contacted. She said officers had been fielding calls throughout the day.
"There have been a few inquiries about things that shouldn't be up on election day but, in the main, people have taken them down again and everything has been fine."
She declined to say where the signs or complaints were, or when the calls occurred.
"Sometimes it's about something that has been inadvertently left up. Sometimes it's about things that were perfectly legal."
She said all problems had been resolved during the day.