Northumbrian Water chief executive Heidi Mottram has been forced to write to a North East MP after he repeatedly blamed the water company for causing an outbreak of sickness at an international triathlon event in Sunderland. Athletes competing in the World Triathlon Championships Series in Sunderland last July fell ill after the race, which included open water swimming at Roker beach. An investigation by the UK Health Security Agency (UKHSA) concluded that the gastrointestinal outbreak was caused by norovirus. However East Durham MP Grahame Morris has continued to blame the water company for polluting the watercourse, which he believed had in turn caused illness.