WASHINGTON (AP) — D.C. Schools Chancellor Kaya Henderson is denying allegations of widespread cheating on standardized tests.

Henderson said in a statement Tuesday that allegations of large-scale test tampering by teachers are “fictitious.”

The school district has recently been challenged over an unusually high number of wrong-to-right erasures on an annual exam.

The D.C. inspector general has found isolated cheating, and the inspector general’s office at the U.S. Education Department announced Monday that an investigation into cheating didn’t identify widespread problems.

Henderson was responding to allegations made in a whistleblower lawsuit and in a “Frontline” documentary by a former principal, Adell Cothorne, who says she came upon staff members surrounded by test booklets and erasers.

Henderson says the school system has no record of Cothorne ever reporting those allegations, as she has maintained.

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