CHICAGO – The man known as Individual A has filed a lawsuit alleging that former U.S. House Speaker Dennis Hastert still owes him $1.8 million as part of an agreement to hide sexual abuse from decades ago when Hastert was Yorkville High School's wrestling coach.

The suit, filed Monday, comes two days before Hastert is scheduled to be sentenced in U.S. District Court on hush money charges.

It was revealed in a court filing last week that an attorney for Individual A sent a letter in January threatening legal action if Hastert did not pay the remaining amount of their $3.5 million agreement. The lawsuit alleges Individual A "suffered severe panic attacks," which led to periods of unemployment, bouts of depression and hospitalization.

Hastert, 74, faces anywhere from probation to five years in prison when he is sentenced Wednesday, although his plea agreement with prosecutors calls for a sentence of no more than six months behind bars.

He pleaded guilty in October to one count of illegally structuring bank withdrawals to avoid reporting requirements, admitting in a plea agreement that he'd paid $1.7 million in cash to Individual A to cover up unspecified misconduct from decades earlier.