In South Australia, gatherings are limited to 10 people and anyone caught breaking the rules faces a $1000 on-the-spot fine.
Police commissioner Grant Stevens said four of the partygoers were issued with warnings.
Three others were slapped with $1000 infringement notices.
In total there were 10 children and seven adults among the crowd.
He said: 'We have a high level of tolerance for people trying to do the right thing.
'But when we see people disregarding the requirements we will take action.'
It comes after another illegal party in Port Augusta which ended in $11,000 worth of fines.
They were warned four times to end the gathering before police began handing out notices.