A $1.8 million civil lawsuit filed by a victim of former U.S. House Speaker Dennis Hastert, convicted of a financial crime linked to sexual abuse of high school wrestlers decades ago, can proceed, an Illinois judge ruled Thursday.

Hastert, 74, once one of the United States' most powerful politicians, was sentenced Wednesday to 15 months in federal prison. During the sentencing hearing, Hastert acknowledged sexually abusing boys when he was a teacher and coach in his hometown of Yorkville, Illinois.

The victim, identified as James Doe, filed the civil lawsuit in Kendall County Circuit Court in northeastern Illinois, claiming Hastert owes him the unpaid portion of a $3.5 million deal they verbally agreed to in 2008 to compensate him for decades of pain and suffering.