Police have arrested a 75-year-old man in connection with the death of a 65-year-old dog walker who was shot dead on a countryside track. The body of Brian Low was discovered in Pitilie, near Aberfeldy in Perthshire, at about 8.30am on 17 February. A postmortem examination carried out six days later established the cause of death as a shooting. During a long-running investigation, known as Operation Newlane, Police Scotland have interviewed more than 800 people. Their inquiries have led them to hundreds of properties in the area and more than 2,000 hours of CCTV footage from dozens of cameras have been viewed. On Friday morning, officers said the 75-year-old man had been arrested and was being questioned by detectives from the major investigation team. Low, who retired from his job as a groundsman at the Edradynate estate in Perthshire last year, had been out walking his black labrador. Police Scotland initially believed his death was “non-suspicious and medical-related”, but a medical examination held six days after his body was found “established he had injuries consistent with being fatally shot”. BBC News has reported that his death certificate confirmed he died of a shotgun wound to the neck and chest. The broadcaster said Low had worked at the nearby Edradynate estate for more than 20 years until his retirement in February last year. It said he lived in Aberfeldy with his partner and died three days before his 66th birthday. Speaking in late February, Ch Insp Greg Burns, the local area commander, said: “I understand this is an extremely concerning incident for a small, rural community.” Shortly after the murder investigation was launched, DCI Martin Macdougall, of the major investigation team, said: “Our thoughts are with Brian’s family at this very difficult time and we are doing all we can to get them answers. We have been carrying out extensive inquiries since Brian’s death and detectives are working alongside uniformed officers to establish the full circumstances.” Scotland’s police watchdog, the Police Investigation and Review Commissioner, has confirmed an investigation is under way after criticism of the way the scene was handled after the discovery of a body. A spokesperson has previously said the watchdog was directed by the Crown Office and Procurator Fiscal Service. The force said it was unable to provide any further comment while the investigation continued.