LITTLE ROCK, Ark. (AP) — A former U.S. attorney from Oklahoma has kept his lobbying contract with a health care nonprofit that is under federal investigation for alleged corruption linked to several Arkansas lawmakers.

Steve Lewis, a former U.S. attorney for the Northern District of Oklahoma, lobbied on behalf of nonprofit Preferred Family Healthcare for years while also serving on its board of directors, the Arkansas Democrat-Gazette reported.

Federal prosecutors have alleged in court filings that the Missouri-based nonprofit concealed its lobbying expenses and spent more money than permitted...