Updated 9.05pm
An individual has been fined €6,000 after being found breaching mandatory quarantine twice in one day.
Health authorities said the breaches were found during more than 400 inspections carried out in the last 24 hours.
Eight other people were also found breaching quarantine.
A 14-day mandatory quarantine currently applies to anyone returning from abroad, those living with them and anyone who has been in contact with a coronavirus patient.
As of Saturday, 21 fines have been meted out for those found breaching the regulations, authorities said.
The Malta Tourism Authority earlier reported that it had carried out 360 inspections of catering establishments and other businesses on Friday but found no breaches of closure regulations.
Bars and restaurants have all been ordered to close to limit the spread of COVID-19, although take-away outlets have been allowed to continue operating. Clubs, cinemas and gyms have also had to shut.