Police are investigating claims that teenage British tennis player Gabriella Taylor was poisoned at Wimbledon last month.

Miss Taylor spent four days in hospital where doctors diagnosed a rare strain of leptospirosis - also known as Weil's disease.

Roger Pickup is a Professor of Environment and Human Health at Lancaster University. He told PM's Eddie Mair that it is more likely that contamination was through the environment rather than human means as this would require specialist kit and knowledge.