The former president of the Massachusetts State Police union and the group's former Beacon Hill lobbyist worked together in a six-year scheme to garner thousands in illegal kickbacks, federal prosecutors allege.

Dana Pullman, 57, of Worcester, who retired as the head of the State Police Association of Massachusetts (SPAM) last fall amid the state police overtime scandal, and Anne Lynch, 68, of Hull, were arrested at their homes Wednesday morning and charged with fraud and obstruction of justice, according to U.S. Attorney for Massachusetts Andrew Lelling.

Pullman and Lynch were to be released on $25,000 bond, after their initial appearance in federal court in Boston Wednesday.

Pullman's lawyer, Martin Weinberg, told The Associated Press that his client strongly denies the charges and "never acted in a manner that compromised his loyalty to his union."

In a statement, Lynch Associates said: "Anne Lynch is no longer affiliated with Lynch Associates and has had no ownership interest in the firm since 2016. She performed consulting services for a limited number of clients until 2018."

Lynch, whom Lelling described as Pullman's "longtime friend," represented SPAM in exchange for monthly retainer payments from 2012 until 2018, when Pullman was the union president. During that time, Pullman received kickbacks from Lynch and her firm, helping him to “line his own pockets with association funds,” Lelling said during a news conference.

According to the criminal complaint, SPAM had filed a grievance alleging that Massachusetts State Police did not properly compensate its employees for working scheduled days off. In 2012, SPAM hired Lynch's lobbying firm to help it build its case. Once a settlement was reached, Pullman allegedly asked SPAM's treasurer to pay the lobbying firm $250,000, on top of $100,000 already paid for its work on the project.

The treasurer complained the SPAM was "getting screwed," but the complaint alleges that Pullman responded to that remark by pounding on the table and yelling "Stop breaking my f---ing balls and give me the check."

After the lobbying firm was paid, Lynch allegedly wrote herself a $50,000 check from the lobbying firm's account, then the following day made a check out to Pullman's spouse for $20,000, according to the affidavit. Officials refer to the checks as a "bribe" and a kickback.

The pair also defrauded two different companies that were trying to secure contracts with the state, Lelling said.

Pullman is also charged with embezzling funds from the union for his own use. Officials say he used the association’s debit card to pay for personal expenses, including $9,000 in flowers for friends and family members, lavish meals like caviar and champagne, and a trip to Miami with a woman he was having an affair with at the time. The U.S. attorney alleges that he submitted expense reports to SPAM without receipts, and encouraged other members of the union to submit false expense reports.

Lelling says Pullman and Lynch later attempted to obstruct the federal investigation by destroying records and lying to law enforcement.

The fraud and conspiracy charges could result in a sentence of up to 20 years in prison, according to the U.S. attorney's office. The charge of obstruction of justice provides for a sentence of up to 10 years in prison.

Lelling noted that it’s been “a rough few years” for state police, citing the overtime abuse scandal also plaguing the agency. “That organization needs to turn a corner and sort of rebuild within,” he said.

He added that public corruption is always a priority for his office, but denied that the case implies a larger crackdown on unions. Earlier this month, two aides in Boston Mayor Marty Walsh's administration were convicted of conspiracy for pressuring concert organizers to hire union workers.

“Based on the complaint, Pullman is victimizing his own membership with assistance from Lynch,” Lelling said, adding that in this case, “we’re on the side of unions.”

In a statement, state police spokesman Dave Procopio said the "conduct as alleged in the criminal complaint represents serious offenses and violates the ideals and values of the Massachusetts State Police. The department has cooperated and will continue to cooperate with the United States Attorney's Office."

With reporting by WBUR's Simón Rios