CHICAGO (CBS) — Just days after resigning from his legislative seat. former Illinois state Sen. Terry Link on Wednesday pleaded guilty to filing a false tax return, admitting he under-reported his income by tens of thousands of dollars in 2016.

According to his plea agreement, Link under-repoted his income in 2016 by $93,859, including $73,159 in campaign funds he spent on personal expenses, causing the IRS and the Illinois Department of Revenue to lose out on a combined $82,660 in lost tax revenue.

Although he pleaded guilty only to filing a false income tax return for 2016, Link admitted in the plea agreement to filing false returns every year from 2012 to 2016.

Link, a Vernon Hills Democrat, resigned from the Illinois Senate last week, nearly one month after he was first indicted.

Under sentencing guidelines in the plea agreement, Link could face up to 16 months in prison, but he is cooperating with federal prosecutors, who indicated they will recommend probation if he cooperates fully.

According to published reports, Link agreed to wear a wire as part of the bribery investigation against former Illinois state Rep. Luis Arroyo, who has pleaded not guilty to bribery charges.

Arroyo, 66, has been charged with one count of federal program bribery. Federal prosecutors said he was caught on tape paying a $2,500 bribe to a state senator who was wearing a wire for the feds.

The feds said Arroyo had agreed to pay the senator $2,500 a month for up to a year in exchange for the senator’s support of sweepstakes-related legislation that would benefit one of Arroyo’s lobbying clients.

The charges against Arroyo did not identify the senator involved in the case, identifying the lawmaker only as “Cooperating Witness 1,” but multiple news outlets have reported that senator is Link.

According to the charges, on Aug. 2, Arroyo offered to pay the senator $2,500 a month for his support for the sweepstakes legislation. On Aug. 22, the two met at a restaurant in Skokie, and Arroyo gave the senator a check for $2,500 as an initial payment, with the expectation Arroyo would continue paying $2,500 a month for 6 to 12 months.

Link allegedly recorded the conversation for the feds. Link had previously publicly denied he is the state senator involved in the case, and although his plea agreement doesn’t make it clear he is involved in the case against Arroyo, it is clear he is cooperating with a federal probe.

Link is the third Illinois state senator to face federal corruption charges in the past year, and the second to plead guilty this year.

In January, former state Sen. Martin Sandoval pleaded guilty to acting as a “protector” for red light camera company SafeSpeed in exchange for thousands of dollars in bribes. He is cooperating with the feds.

Last September, state Sen. Thomas Cullerton was indicted on charges he embezzled more than $250,000 in salary and benefits from a local Teamsters office, even though he did little or no work for the labor union. Cullerton has pleaded not guilty.