Former British athlete Diane Modahl has called for care to be taken with the allegations made towards coach Alberto Salazar.
Salazar, who has trained Mo Farah since 2011, has been accused of encouraging doping among his athletes at his training facilities in Oregon, while 10,000m runner Galen Rupp is also implicated in the investigation conducted by BBC's Panorama programme.
However, Modahl, who was falsely accused of doping in 1994, believes that proof is "essential" before judgments can be made about Salazar.
The 48-year-old is quoted by BBC Sport as saying: "Proof is essential when it comes to protecting innocent athletes.
"We cannot convict on gossip, on hearsay or rumour. We have to be very, very careful in terms of what we say and what we are actually accusing people of."
Salazar has denied the allegations, while there have been no suggestions that Farah has broken any rules.
