An indictment by a federal grand jury could be returned as soon as Monday in the Churchill Downs sponging case, according to a report by ESPN cited by the Associated Press.

ESPN reported that law enforcement officials stated that the alleged perpetrator is “an industry insider with daily access to the horses and grounds.” An indictment in the case, which involves sponging incidents going back to the spring of 1996 at Churchill, could involve possible charges of tampering with interstate commerce.

Sponges, which probably were used to try to influence the outcome of races, restrict a horse’s air flow by as much as 50% when inserted in the animal’s nostrils. One horse, Class O Lad, developed laminitis after being sponged, and was subsequently euthanitized