POLICE busted a drug dealer after spotting tell-tale white powder round his nose. Callum McMahon was arrested on his first – and last – day in the cocaine dealing business, Reading Crown Court heard. Paul Lennon, prosecuting at a sentencing hearing on Friday, March 8, said police responded to reports of illegal activity at a drugs den near the 26-year-old’s Claremont Crescent home in Newbury. He added: “The defendant was searched in the driveway; he appeared to be under the influence of drugs and there was white powder under his nose.” As officers began to search McMahon, went on Mr Lennon, “i…