Coe can't guarantee clean World Champs
IAAF President Sebastian Coe has said that he cannot guarantee that next month's World Athletics Championships in London will be drug free.
"It's a very Utopian view. People will always seek to cheat," said Coe in an interview with BBC One's Andrew Marr Show.
However, Coe said that the system for detecting cheats is a lot safer.
"We have the technology that allows us to be very much more specific about what we are looking for," he said.
"I would love to tell you that we will have a drug-free sport in future. Everything we are doing is engaged in trying to achieve that, but we know a few people will cheat," Coe said.
He added: "What we do have in place now is an independent athlete integrity unit. We have independent sanctioning and discipline, and we will be able to be a lot tougher and speed up the process."
Russia's athletics federation is banned from the event in London, having been suspended by the sport's global governing body in 2015 amid allegations of state-sponsored doping.
Russia was barred from international athletics after last year's McLaren report claimed that more than 1,000 athletes benefited from a state-sponsored doping programme between 2011 and 2015.