Cook County Forest Preserve District officials say a pay raise of nearly 10% given to one of Cook County Board President Toni Preckwinkle’s security guards was an “administrative error” that the guard will have to repay.

Rodney Montgomery’s salary went up 9.65% — to $110,396 from $100,680 — when he and other members of Preckwinkle’s security detail were transferred last year from a county department to the forest preserves police department, the Chicago Sun-Times reported earlier this month.

That was the biggest raise given to members of Preckwinkle’s security detail, which was moved to the forest preserves police after a scandal forced out the detail’s former chief.

Officials say the unusually large pay bump happened because Montgomery mistakenly received two “step” raises awarded for experience in the same year — one in April, on the anniversary of when he started at the county’s Department of Homeland Security, and another in September, when the Preckwinkle security jobs were shifted to the control of the forest preserves.

Montgomery should have gotten just one of those increases, according to forest preserves spokesman Carl Vogel.

“The forest preserves has now corrected this error, and Montgomery’s salary is at the correct level: $105,344,” Vogel said. “We are unaware of any similar errors.”

Montgomery was hired for Preckwinkle’s security detail in May 2017 at a salary of $97,607. He previously had worked since 2009 for the forest preserves police, where he was making $54,000 a year.

Addressing the pay raise for the first time, Preckwinkle said Thursday, “It’ll be corrected, and he’ll have to pay the money back.”

She said the decision to move the detail was to ensure that her guards have law enforcement powers.

“I have three members of my detail and a couple people who fill in from time to time,” Preckwinkle said. “Frankly, I would just say, without making any comparisons, that my detail is very modest when compared to other elected officials.”

In September 2018, members of Preckwinkle’s detail were shifted to the forest preserves police. That came months after her former security chief Delwin Gadlen was fired. His dry-cleaning receipt along with campaign materials that included a button with Preckwinkle’s face and sample ballots, had been found in a county vehicle abandoned in a ditch in Lemont in 2016.

Other members of Preckwinkle’s detail also got pay increases. Philip Mason’s pay went up 4.8%, to $110,396 from $105,343. He’s been part of the Hyde Park Democrat’s detail since November 2013, when he was making $75,017.

Leesandra Rios-Torres also got a 1% raise, to $114,878 from $113,740. Part of Preckwinkle’s security team since 2011, Rios-Torres was being paid $84,556 a year at the end of 2014, when the detail was shifted from the Cook County sheriff’s office to be under Preckwinkle’s control.