Manchester United have reportedly triggered a clause in the deal that saw Romelu Lukaku move to Inter which puts the Serie A club in £43million of debt to the Old Trafford club.
Lukaku moved to Inter in the summer of 2019 for a deal worth a reported €80m.
Corriere dello Sport now claim that the deal included a clause that meant if Inter missed any payment deadline they would immediately have to pay United the remaining amount.
The report alleges that the Italian club have missed one of those payment deadlines in the midst of financial issues and are now in €50m (£43m) worth of debt to United.
With the clause triggered, United are said to be pressurising Inter to pay them off.
One resolution United are said to be pushing for is for Inter to allow either Milan Skriniar or Lautaro Martinez to leave for Old Trafford, with both players reportedly admired by Ole Gunnar Solskjaer.
Although both players have higher values than the remaining money owed from the Lukaku deal, United are said to be willing to pay an additional fee and are in a strong position given the debt.
The report claims the solution to the problem was raised in the last few days, with the clubs in contact over the situation.