GlaxoSmithKline has fired former U.S. vaccine czar Moncef Slaoui as chairman of a company it controls following an inquiry that substantiated accusations of sexual harassment against him, KBTX-TV and Ars Technica reported Thursday.

Slaoui, who headed the coronavirus vaccination development efforts under the Trump administration, said he was "deeply sorry" to a woman whose allegations of sexual harassment led to his termination Wednesday as chairman of Galvani Bioelectronics' board of directors.

"I have the utmost respect for my colleagues and feel terrible that my actions have put a former colleague in an uncomfortable situation," Bloomberg News quoted Slaoui as saying.

GSK said it received a letter from one of its staff containing claims of sexual harassment and "inappropriate conduct" by Slaoui, which took place several years ago while Slaoui was working there.

The woman made the accusations in a letter sent to GSK in February. Morgan, Lewis & Bokius, a law firm hired by the pharmaceutical company, is investigating her claims.

"Slaoui's behaviors represent an abuse of leadership position and violate our company policies, values and our commitment to trust," The Detroit News quoted Emma Walmsley, Glaxo's chief executive officer, as saying in a letter to employees.

Slaoui said that he is taking a leave of absence from positions at other health companies to focus on his family, to whom he also apologized.

The 61-year-old immunologist, who spent 30 years at GSK, was head scientist for the Trump administration's Operation Warp Speed, the U.S. government's program to develop COVID-19 vaccines.

Walmsley said GSK is renaming its research and development facility in Rockville, Maryland, which had been called the Slaoui Center for Vaccines Research.