Attorney General Alan Wilson made that announcement on Monday. A month ago, Wilson's office received what it called a "voluminous" report from the State Law Enforcement Division.
At Wilson's request, state police began looking at the case after South Carolina Policy Council President Ashley Landess alleged the Charleston Republican used his office to boost his finances by using influence to get a permit for his pharmaceutical business.
The libertarian think tank also took issue with Harrell appointing his brother to a committee that screens judicial candidates.
A spokesman for Harrell didn't immediately return a message seeking comment.