After being placed on administrative leave earlier this week, Brookings Institution president John Allen has resigned, the Associated Press reports. The retired four-star Marine general’s resignation comes amid a federal investigation into alleged illegal lobbying work he did on behalf of Qatar, evident in new court filings that AP first wrote about last week. According to the court filings, the FBI seized some of Allen’s electronic data in its investigation, which probes whether the now-ex Brookings president advised top Qatar officials on how to influence U.S. policy. In an affidavit supporting a search warrant, an FBI agent claimed that there is “substantial evidence” that Allen consciously broke foreign lobbying laws. Allen, who has served as Brookings’ president since 2017, has not been charged with any crimes and, through a spokesperson, maintained that he has done nothing wrong. He did not provide a specific explanation for his resignation.