Hearts have been ordered to pay outstanding monies to their players within seven days, the Scottish Premier League announced on Wednesday.
An SPL sub-committee met after players' union PFA Scotland submitted a formal complaint on behalf of Hearts' first-team squad on December 16, when wages were not paid on time for a third consecutive month.
December's pay remains outstanding and the SPL have made a series of demands in order to halt the financial uncertainty surrounding the club.
An SPL statement read: "An SPL board sub-committee today [Wednesday] adjudicated in the dispute between 14 players and Heart of Midlothian FC. The SPL board sub-committee has ordered December wages to be paid by January 11.
"Interest on all sums overdue from October, November and December wages must also be paid by January 11. January salaries must be paid on time on January 16.
"The club must also pay the claimants' legal expenses and the SPL's costs of today's hearing. Both sides have the right to appeal the decision to the Scottish FA within seven days.''
Should Hearts fail to meet the deadline, fresh disciplinary proceedings would be opened, with unlimited sanctions available to the SPL at that point.
SPL chief executive Neil Doncaster said in a statement: "Today's decision demonstrates how seriously the SPL take late payments of wages to players.''
Hearts have avoided answering questions on the subject as a result of a media blackout, which has been in place since October 22.
The club this week partially lifted the media blackout by speaking to match broadcasters after their 3-1 Edinburgh derby win at Easter Road.
Manager Paulo Sergio told BBC Scotland he was expecting a difficult month with players expected to depart to reduce the wage bill.
Eggert Jonsson has already joined Wolves and Ryan Stevenson is on self-imposed leave with six months remaining on his contract after expressing his frustration at the financial uncertainty at the club.