The Hearts first-team squad and PFA Scotland have submitted a formal complaint to the Scottish Premier League over unpaid wages at the club after the players' December salaries failed to arrive on schedule.
The Hearts squad experienced a delay in the delivery of their wages for the third successive month and, after instructing players' union PFA Scotland to act for them on Thursday, they have taken their fight to the authorities.
It is anticipated the matter will be discussed at Monday's SPL board meeting, where all the Clydesdale Bank Premier League clubs will be represented.
The SPL confirmed receipt of the letter in a statement.
The statement read: "The SPL received a letter from PFA Scotland this afternoon on behalf of several PFA members. This letter will be considered by the SPL Board at its meeting on Monday. No further comment will be issued at this time."
The Hearts players signed a letter of permission allowing PFA Scotland to represent them in their battle to recover their owed monies after growing tired of the ongoing uncertainty at the beleaguered club.
Wages are due on the 16th of each month, but the first delay saw their October salary received on November 4. On that occasion the intervention of manager Paulo Sergio stalled a complaint and 24 hours later payment was made.
Last week the players received a £1000 part-payment from funds generated from the loss to St Johnstone at Tynecastle and on Thursday the November salaries were paid in full - 29 days late.
However, there was no sign of further payment on Friday and PFA Scotland chief executive Fraser Wishart made formal the players' displeasure by delivering a letter of complaint to the SPL's Hampden Park offices.
Hearts director Sergejus Fedotovas, who issued a robust defence of the club's stewardship under owner Vladimir Romanov, and managing director David Southern are understood to have met the squad in an unsuccessful attempt to avert action.