* USADA says left no stone unturned
* WADA wants to see which athletes benefited from programme (Adds WADA reaction)
By Karolos Grohmann
KATOWICE, Poland, Nov 6 (Reuters) - There is no point in the World Anti-doping Agency (WADA) looking into athletes who trained under banned coach Alberto Salazar because the U.S. Anti-doping Agency has already done that, USADA chief Travis Tygart said on Wednesday.
WADA chief Craig Reedie said this week the anti-doping body would begin investigating the athletes who are part of the Nike Oregon Project (NOP).
Salazar, who counts Britain's Olympic and world champion Mo Farah among the top distance runners he has coached, was last month banned for four years by USADA for doping violations.
However, USADA did not sanction any of his athletes after finding no evidence of any wrongdoing by them.
"That was the first thing to come out of WADA after the USADA decision. I don't know why they said that. It was surprising," Tygart told Reuters on the sidelines of a world conference on doping in sport organised by WADA.
He said he had asked WADA to operate as observers in this case.
"What they (WADA) would have learned is that we left no stone unturned (in relation to any athletes)," Tygart said. "Several athletes have asked us what it (WADA decision) means for them.
"I could not possibly say why WADA said that."
Tygart has had an uneasy relationship with WADA in recent years and has remained critical of the body's handling of a major Russian doping scandal.
Outgoing WADA chief Craig Reedie said his organisation was merely exercising its right to look into what he said was "an unusual" case.
"Travis would say that, wouldn't the?," Reedie told reporters. "We as regulators have the right to appeal. We will get the file. We will look into the situation. It is an unusual one."
WADA Director General Olivier Niggli said it was important to determine who benefited from Salazar's actions.
"Given that Mr Salazar ran a programme, we would like to know who were the beneficiaries of the programme," Niggli said.
American Salazar, who won three consecutive New York City marathons starting in 1980, has vowed to appeal his ban.
Nike has since shut down its Oregon Project for elite long-distance runners, calling it a "distraction" for the athletes. (Reporting by Karolos Grohmann, Editing by Christian Radnedge and Ed Osmond)