SIOUX FALLS, S.D. (AP) — Sanford Health has fired one of its surgeons who is the subject of a federal fraud investigation, a month after three top hospital executives defended him against the allegations.

Neurosurgeon Wilson Asfora owns a company that sells devices used in spine surgeries. Two Sanford doctors in 2016 filed a lawsuit accusing Asfora of illegally profiting by using those devices in unnecessary spine surgeries at Sanford Health in violation of anti-kickback laws. The U.S. Department of Justice is investigating.

Asfora’s attorney, Steve Landon, told the Argus Leader this week that the surgeon’s termination is effective Sept. 24.

“Dr. Asfora received notice of termination from Sanford— he is not resigning or retiring,” Landon said. “Like Sanford, he believes the allegations made in the lawsuit are bogus and he will vigorously defend against them.”

Sanford Health didn’t respond to the newspaper’s request for comment.

Last month, Sanford CEO Kelby Krabbenhoft, Chief Operating Officer Matthew Hocks and Chief Medical Officer Allison Suttle sent an email to employees, calling the allegations against Asfora “bogus.”

Earlier this month, the hospital suspended its use of some of Asfora’s medical devices. Micah Aberson, Sanford’s executive vice president said the suspension was not related to deficiencies or clinical outcomes.

“The distraction of the economics related to the device is what we want to remove from the conversation,” Aberson said last month.

Sanford settled a similar whistleblower lawsuit in 2014 after a former Sanford Health employee made similar accusations that Asfora was improperly profiting from one of his medical devices.