Washington, Jan 2 (IANS): The Pentagon's top spokeswoman, who was under investigation over misconduct allegations, has resigned.

Dana W. White announced her resignation on Twitter on Monday night, hours after outgoing Defence Secretary James Mattis sent his farewell message to department employees.

"I appreciate the opportunity afforded to me by this administration to serve alongside Secretary Mattis, our service members and all the civilians who support them. It has been my honour and privilege. Stay safe and God bless," White said on Twitter.

A Defence Department spokesperson on Tuesday confirmed White had resigned from her position as assistant to the Secretary of Defence for Public Affairs, the Washington Post reported.

Charles E. Summers Jr. replaced White, becoming "acting" assistant to the Defence Secretary, the Pentagon said. He is a graduate of the University of Illinois at Urbana-Champaign and holds the rank of captain in the US Navy Reserve.

It was not clear whether White's departure was related to reports of the probe by the Inspector General to determine whether she mistreated staff members or retaliated against them after they raised concerns, according to the Post.

Six current and former Pentagon officials had said at least two complaints were filed against White. The probe focused in part on how staff members carried out personal tasks for her.

At least five staff members had been abruptly transferred or removed from their jobs since White took over in April 2017.

White was also a foreign policy adviser on the 2008 presidential campaign of Senator John McCain and an editorial writer for the Wall Street Journal based in Hong Kong.