AUGUSTA, Maine — The Maine Turnpike Authority has filed a lawsuit against its former executive director in hopes of recovering approximately $450,000 in undocumented and unauthorized expenses.

The turnpike authority filed the civil lawsuit Tuesday in Cumberland County Superior Court against Paul Violette, who stepped down after 23 years on the job when allegations of financial misconduct surfaced in March.

The lawsuit seeks repayment from Violette for personal expenses and reimbursements he charged to the authority from 2003 to 2010, all of which were detailed in a forensic audit of the agency’s finances. That forensic audit was solicited by MTA board members following a January report by Maine’s Office of Program Evaluation and Government Accountability that uncovered questionable spending practices at the state agency.

Violette is suspected of questionable spending practices, including the purchase of $150,000 in gift cards to posh hotels and restaurants that were donated to other organizations, unrelated to turnpike business.

In addition to the alleged abuse of gift cards and agency credit cards, the lawsuit claims Violette was paid for $160,000 in vacation and sick time to which he was not entitled. The lawsuit further alleges that Violette acted with malice because he knew his conduct would cause harm to his agency.

The state Attorney General’s Office has been looking at criminal charges against Violette but has yet to levy any.

Peter DeTroy, Violette’s attorney, said Tuesday he was not surprised a civil lawsuit was filed, but he could not comment on the allegations because of the investigation.

The Maine Turnpike Authority is responsible for management of more than 100 miles of interstate from Kittery to Augusta. The agency employs 470, collects approximately $100 million in tolls every year and is overseen by a seven-member board whose members are appointed by the governor.

Violette had run the turnpike authority since 1988, but the allegations of financial wrongdoing date back only about eight years.

The OPEGA report presented to the Legislature’s Government Oversight Committee in January asked numerous questions about the authority’s service contracts, its operating budget and its policies on travel and meal expenses. What generated that most attention though, was Violette’s distribution of gift certificates the turnpike authority said were donated to organizations but were unaccounted for. Violette reportedly redeemed a number of those cards himself to pay for family vacations in Maine and overseas in countries like Italy and Bermuda.

When he stepped down, Violette, a former lawmaker from Van Buren who served in the 1980s, submitted a letter of resignation to the authority’s board.

“I believe my continued leadership has become a distraction, causing those positives to be obscured and implementation of those recommendations to be delayed,” Violette said in the letter, referring to the non-negative elements of the OPEGA report. “It is my hope that my resignation and the appointment of an able replacement will allow the focus to return to ways in which the Maine Turnpike Authority may continue to improve.”

During an April hearing of the Government Oversight Committee, Violette was asked to explain the allegations but refused to answer any questions.

On the same day the suit was filed, longtime lawmaker Peter Mills, who took MTA’s reins earlier this year, testified to the Legislature’s Government Oversight Committee about steps the agency is taking to avoid future problems.

“I made the case that we need to have a program of internal auditing, something that is  routinely done in banks,” Mills said Tuesday after the hearing. “There are other agencies of state government that likely could use that sort of scrutiny.”

Sen. Roger Katz, R-Augusta, co-chair of the Government Oversight Committee, said the committee supports the lawsuit because it is trying to recoup the misused public money.