London 2012: Paula Radcliffe talks about drugs in sport
British long distance runner Paula Radcliffe has campaigned against the use of performance-enhancing drugs throughout her career.
But on the eve of the London Olympics, Moroccan runner Mariem Alaoui Selsouli was kicked out of the games after failing a drugs test, showing the fight for clean competition is far from over.
BBC Newsnight science editor Susan Watts visited Paula Radcliffe's altitude training camp in the Pyrenees to talk to her about doping and her personal hopes for the Olympics.
You can see Susan Watts' report on drugs in sport on Wednesday 25th July 2012 on Newsnight at 10.30pm on BBC Two, and afterwards on BBC iPlayer and the Newsnight website.
25 Jul 2012