The state Department of Transportation has ended its agreement with the Department of Public Safety to have deputy sheriffs handle law-enforcement duties at the Daniel K. Inouye International Airport, and state Sen. Will Espero is questioning whether the move is payback for a lawsuit filed by the sheriffs’ union to block the state’s new contract with a private airport security firm.

Deputy sheriffs have been used to provide security for the airport since 2002. On Thursday, DOT officials sent DPS a required 180-day notice of its intention to terminate the agreement.

DPS has 57 deputy sheriffs and two civilians assigned to the airport.

The private company Securitas has played an expanding role in providing security services for the airport.

Last year, DOT reached a three-year contract extension agreement with Securitas worth a reported $35 million a year. The extension came despite the indictment of four Securitas employees for soliciting and taking bribes from taxi and shuttle drivers at the airport.

At the time, DOT spokesman Tim Sakahara said using the private security firm was cheaper than hiring more deputy sheriffs.

Securitas has come under increased scrutiny over the past year for its hiring of former law enforcement officers who had been terminated from their previous jobs because of misconduct and for a recent incident in which a Securitas employee shot and killed a pet dog owned by a passenger’s family.

Last summer, the Hawaii Government Employees Association, which represents state deputy sheriffs, sued in an attempt to block the state’s contract with Securitas, alleging that broader powers granted to private security officers were creating safety issues and, in turn, leaving the state vulnerable to litigation.

In an email to the Star- Advertiser, Espero said ending the agreement with DPS “is wrong,” adding, “I question the decision and wonder if this decision might be punitive in nature.

“State sheriffs should be at this state facility,” Espero said. “If any contract should be reviewed, it should be the contract for private security work at the airport.”

He said the decision could also negatively affect the displaced deputy sheriffs.

“Basically some sheriffs may be out of a job just before Christmas,” he said. “I’m told newer sheriffs and those in school will be impacted. (There are) limited places to put them.”

DPS spokeswoman Toni Schwartz referred inquiries about the contract situation to the Transportation Department.

DOT officials did not respond to a request for comment.