Former Inspector General Steve Linick told Congress last week that two senior officials sought to block an inquiry into the arms deal, according to a transcript of the interview made public.
The investigation is part of a larger congressional efforts to find out more about President Trump’s recent moves to sideline several independent government watchdogs.
The secretary of state says he was unaware of any inspector general investigation into allegations that he may have mistreated staffers by instructing them to run personal errands for him and his wife.