The operator was fined €15,000 (£12,867/$16,174) for a breach related to payments and depositing into an online account.
An Authority-led investigation found an individual had been topping up the balance of two other players’ accounts with Top Sport using his own payment cards.
The regulator said that as Top Sport did not ensure only the accountholder was depositing into their own account, this was in breach of gambling law.
Specifically, it was deemed a breach of Article 205, Paragraph 1 of the country’s Law on Gambling.
This marked the third fine of the week for Top Sport following two other breaches of gambling law.
Top Sport began the week with a €25,000 fine for allowing underage individuals to enter one of its slot salons.
An investigation found that three people, at least one of whom was a minor, were able to enter the facility and remained inside for more than two hours. The Authority said Top Sport did not take any measures to remove the three people from its premises.
The following day, Top Sport was fined a further €15,000 after it breached regulations on mobile betting.
The Authority found that bets were being automatically placed on Top Sport’s betting app. After a user placed bets on a live roulette table supplied by Ezugi, once they had locked their phone, the app automatically repeated the bet.
The latest fine means penalties for Top Sport in the past week amounted to €55,000.