OKLAHOMA CITY — The FBI is investigating a cybertheft of $4.2 million from the state’s pension fund for retired Oklahoma Highway Patrol troopers, state agents, park rangers and other law enforcement officers.

The Oklahoma Law Enforcement Retirement System — OLERS — posted an announcement online about the investigation Thursday, 10 days after the money disappeared from the account.

“We are certain the stolen funds will be recovered,” the state agency said. “Most importantly, no pension benefits to members or beneficiaries have been impacted or put at risk. All benefits will continue to be paid in a timely fashion as always.”

The state agency made the announcement only after being contacted by The Oklahoman about the cybercrime.