Prominent businessman Mark Bouris has breached electoral laws by robo-calling voters to warn them against voting for Labor, the electoral watchdog said on Thursday.

Voters across the country received a voice message from Bouris, former host of The Apprentice, warning them not to vote Labor, because its negative gearing policy would cause house prices to plummet.

“If Labor wins and they bring in negative gearing changes and the capital gains tax changes, house prices will fall, they’ll continue to fall at a very rapid rate,” he warned. “And what’s worse our kids are going to have to pay more rent because investors are going to have to put the rent up to recoup the losses they would normally get as a tax deduction.”

The voicemail contained no authorisation, leaving voters unable to determine whether Bouris was speaking on someone else’s behalf.

The Australian Electoral Commission said the failure to include an authorisation represented a “technical breach of the authorisation requirements”. It said it would be contacting Bouris to remind him of his obligations.

“This is an electoral communication that requires an authorisation because it advises against voting for the ALP,” a spokesman said. “As you note the authorisation must be at the start of the call and only needs the caller’s name and town or city in which they reside (unless doing on behalf of another organisation in which case the details of the organisation are required).

“We will remind Mr Bouris of the authorisation requirements.”

Bouris is best known for his role founding Wizard Home Loans in 1996, but currently runs Yellow Brick Road, a wealth manager and finance planner. Bouris was approached for comment.

It was the second time this week that the AEC has had to warn political campaigners about their election material. The Liberal party was warned about display ads appearing across major news websites, which failed to carry the proper authorisation.

Authorisations are important because they help voters work out who is behind a particular political advertisement. Without authorisations, hidden or unsourced actors are able to exert influence over voters with no transparency. Authorisations also help the AEC monitor and regulate content.

Enforcement of the authorisation requirements, however, is sporadic and generally non-punitive. The AEC often relies on public tip-offs to detect authorisation failures.

The watchdog did not flag any punishment for Bouris, despite the breach.