Reni Maitua, Tautau Moga and Sauaso Sue have been fined $10,000 each for their roles in a late night incident in Brisbane last weekend, the NRL announced.
Rugby League Samoa had already suspended each of the three players for one game – the Four Nations opener against England on Saturday.
The NRL's General Manager of Integrity, Nick Weeks, said the NRL will not tolerate player misbehaviour.
In determining the level of fines, the NRL had taken into account the salaries of the players involved.
"In other words, these are very substantial penalties for the players involved," Mr Weeks said.
"And we will continue to take a tough stance against players who damage the reputation of our game through these kinds of incidents."