National MP Tim Macindoe has been referred to police by the Electoral Commission over a radio advertisement broadcast on Free FM.
The broadcaster has also been referred to police.
The Electoral Commission said it believed the advertisement constituted a breach of the Broadcasting Act as an election programme cannot be broadcast at any time on radio or television other than during the official election period - which runs from August 20 to September 19.
The advertisement also failed to include a promotor statement, which is another legal requirement.
Macindoe said the advertisement was no longer on air.
"I have taken all steps to provide the Electoral Commission with information about my advertising to ensure compliance. I'm embarrassed to be in this position and I apologise for it."
He could make no further comment while the matter was with police.
The offence carries a penalty of up to $100,000.
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