DUBLIN, Calif. (AP) — The Justice Department says it is gravely concerned about allegations that a high-ranking federal prison official entrusted to end sexual abuse and cover-ups at a women’s prison may have taken steps to suppress a recent complaint about staff misconduct.

Deputy Regional Director T. Ray Hinkle is accused of attempting to silence a female employee who said she had been harassed by a manager the federal correctional institution in Dublin, California, by meeting with her personally in violation of established protocols.

Four workers at Dublin, including a warden, have been arrested in the last eight months and charged with sexually abusing inmates. Several others are under investigation.