Manly Sea Eagles face NRL sanctions after the league's governing body found evidence of potential salary breaches over the last five years.
The NRL hit the Sea Eagles with a breach notice on Monday following the conclusion of its investigation into salary cap issues at the club.
In a statement, the NRL said "should these preliminary findings be confirmed, proposed sanctions could include a significant fine on the club", while the Sea Eagles could also be required to adjust their salary cap for the 2018 season.
Show cause notices have also been issued to two current club officials asking why their registrations should not be cancelled.
The Eagles have five days to respond, though NRL chief executive Todd Greenberg said "given the seriousness of the allegations, the NRL would consider a request for an extension of time."
In 2016, Parramatta Els were docked 12 competitions points and fined 1,000,000 Australian dollars for salary cap breaches dating back to 2013.