WASHINGTON _  Acting Food and Drug Administration commissioner Janet Woodcock on Friday sought a federal probe into the agency’s approval last month of Biogen Inc.’s controversial Alzheimer’s disease drug Aduhelm.

In a letter to the Office of Inspector General, Woodcock requested that the independent watchdog investigate the interactions between the drugmaker and the FDA  during the lead-up to the accelerated approval of Aduhelm.

“There continue to be concerns raised … regarding contacts between representatives from Biogen and FDA during the review process, including some that may have occurred outside of the formal correspondence process,” Woodcock wrote in the letter _ posted on her Twitter account _ to acting inspector general Christi Grimm.

According to reports by Stat News, FDA officials worked closely with Biogen executives to get the drug okayed. Aduhelm was the first Alzheimer’s drug approved in nearly two decades, and the agency was being pressed by patients’ family members and advocates to authorize a new treatment.

“To the extent these concerns could undermine the public’s confidence in FDA’s decision, I believe it is critical that the events at issue be reviewed by an independent body such as the Office of Inspector General in order to determine whether any interactions that occurred between Biogen and FDA review staff were inconsistent with FDA policies and procedures,” Woodcock wrote.

The drug’s approval came despite the near-unanimous objections of an FDA expert advisory committee. Three of the agency’s outside advisers quit over the decision.