(CNN) More than a dozen correctional employees in Illinois are under investigation after they were accused of mocking transgender inmates in private Facebook groups, state officials said.

Earlier this week, a review by Injustice Watch , a nonprofit journalism organization, found that at least 25 employees with the Illinois Department of Corrections -- including prison guards, a counselor and a parole officer -- have participated in online conversations that included degrading comments or disclosed medical information about transgender inmates in two private Facebook groups. The posts included references to transgender women as "it" and "he."

"Know matter way you look at it, it's a freak'n male inmate," a correctional officer commented on a post of a news story about an incarcerated transgender woman who had been suing several prison employees for cruel treatment and sexual assault.

"Transgender's are a f***** joke in my view," he added.

The private Facebook groups, "Behind the Walls - Illinois Dep't of Corrections" and "Behind the Walls ~ Illinois Department of Corrections," have each more than 4,000 members.

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