Hearts have failed to pay all of their players for the second month in succession, according to reports from STV and Press Association Sport.
The wages were due on October 16 but six of John McGlynn's squad have not received their pay packet in full and the club are in the process of informing the Scottish League in accordance with the SPL rules.
The Edinburgh club were repeatedly late in paying players last season, with three consecutive delays, and were charged "with failing to behave with the utmost good faith to the Scottish Premier League", although no penalty was imposed.
Hearts also had problems in September after eight members of staff were not paid on time but they settled the overdue bills.
The Scottish Premier League have been told of the recent hold-up, and Hearts will be required to respond to the incident by Friday.
Last season, the PFA Scotland lodged a complaint on behalf of the players to the Scottish Premier League over three months of unpaid wages. However, on that occasion, Hearts met the demands in January.