District officials fired the investigator probing alleged misconduct at McKinley High School on Friday, one day after he admitted lying to an interview subject by claiming that the school system’s chief of staff wanted to quash the inquiry.

Officials said Eastern Stewart, an investigator for the school system’s security division, was dismissed for telling a former McKinley teacher that Lisa Ruda, chief of staff to acting Chancellor Kaya Henderson, wanted to “push under the rug” a probe into allegations that Principal David Pinder had improperly paid teachers and mishandled a $100,000 award from AARP.

“She wants to cover it, push it under the rug. She’s trying very hard not to get this exposed,” Stewart told former McKinley teacher Thomas Ammazzalorso, suggesting that Ruda made the comments after he had briefed her on the case. The statements can be heard on an audio recording of the Jan. 12 interview made by Ammazzalorso. He provided a copy of the recording to The Washington Post.

When asked about the comments Thursday, Stewart said they were merely an investigative technique he employed to test the trustworthiness and credibility of Ammazzalorso.

“I have never spoken to Lisa Ruda about this case,” Stewart said. Stewart’s supervisor, school security chief John Harris, said he never discussed the use of such an approach with Stewart.

The tactic infuriated Ruda, who vehemently denied Stewart’s allegation in an interview Thursday and repeated the denials through a spokeswoman Friday.

“While the investigator’s admission makes unequivocally clear that the allegations [of a coverup] are false, Lisa is disappointed that her time and that of other DCPS staff members was devoted to refuting these allegations as opposed to the ongoing work of supporting our students and schools,” spokeswoman Safiya Simmons said in a statement.

Simmons said the school system general counsel Robert Utiger and the school security office would work to see that ongoing investigation into alleged misconduct at McKinley is “completed in a timely and professional manner.”

The firing of Stewart capped a turbulent two weeks at McKinley, a selective, application-only high school in Northeast Washington. Pinder was placed on paid administrative leave by Henderson on Wednesday because of allegations that Pinder had doctored student transcripts to award credit for courses never taken.

On March 15, acting D.C. Attorney General Irvin B. Nathan referred the findings of Stewart’s investigation into the AARP award to the U.S. attorney’s office, saying saying that funds “may have been mishandled.” The money was intended to fund a community service program in which McKinley residents were to tutor senior citizens in how to use the Internet. Stewart has said a portion of the $100,000 is unaccounted for.

According to school officials, the McKinley investigation began last summer when a staff member in the office of Chief Financial Officer Natwar Gandhi reported that a teacher may have fraudulently claimed payment for summer school hours he did not work. The charge was not substantiated, but in the course of that inquiry, Stewart began to develop information about the AARP grant and other financial activities at the school, officials said.

Pinder could not be reached for comment Friday. Stewart, who did not return a cellphone message Friday, is a former Air Force and D.C. police investigator who joined the school district in August 2010.

Ruda, through a spokeswoman, expressed frustration on Friday about the handling of the McKinley investigation.