The House Ethics Committee ended a four-year probe into Republican Rep. Vern Buchanan of Florida, finding no evidence that the lawmaker violated House rules.

The ethics panel said in a report on Friday that there is not enough evidence to conclude that Buchanan himself was aware of unlawful payments made by companies affiliated with him to reimburse campaign contributors. Still, the committee cautioned Buchanan to “exercise more diligence over affairs related to his campaign.”