Washington (CNN) The Department of Defense's Inspector General announced Thursday that it has cleared acting Defense Secretary Patrick Shanahan of allegations he violated ethics agreements by promoting the interests of his former employer, Boeing.

The Inspector General "did not substantiate any of the allegations and determined that Acting Secretary Shanahan fully complied with his ethical obligations and agreements regarding Boeing and its competitors," according to a statement from the Pentagon. More than 30 witnesses, including Shanahan, were interviewed by the IG's office, according to the statement.

"The Office of Inspector General took these allegations seriously, and our 43-page report of investigation, which we released today, describes our conclusions and the facts on which they are based. The evidence showed that Acting Secretary Shanahan fully complied with his ethical obligations and ethical agreements with regard to Boeing and its competitors," Glenn Fine, the IG official who oversaw the investigation, said in an additional statement.

CNN has previously reported that if Shanahan is cleared of the allegations, President Donald Trump may decide to move ahead and send his nomination to the Senate to become the permanent defense chief.

So far, there are no indications that the White House is considering candidates other than Shanahan. Officials close to the acting secretary say he strongly believes he will be nominated by the White House.

Read More