Clayton — An undercover drug investigation led to the arrest of a Clayton man April 3, police reported.Robert “Robbie” Worrells, 50, of 210 S. Robertson St., was served with nine warrants for three counts each of possession with intent to sell and deliver cocaine, selling cocaine and maintaining a dwelling for a controlled substance. Also, he was served with two probation violation warrants, according to the Clayton Police Department. Worrells was taken to Johnston County jail and placed under a $250,000 bond.The warrants stemmed from the department’s undercover operation that began last year. Police found 7 grams of marijuana and drug paraphernalia at Worrells’ home Thursday.