PyeongChang scandal continues with 15 positive tests returned

Questions over the integrity of sample-collection bottles led to frustration from athletes at this year's Winter Olympics, including two who tightened their bottles so tightly, they cracked the caps.

That is one conclusion from the independent report released on Thursday about the anti-doping operation in PyeongChang.

In all, there were 3,189 tests conducted that led to 15 positive tests, six of which led to anti-doping rules violations that were upheld.

Two of those involved Russian curler Alexander Krushelnitsky, who gave back his bronze medal after testing positive for meldonium.

Among the athletes' top concerns was the integrity of the urine-collection bottles , which were found to be susceptible to being opened without leaving any evidence.

The report said this "created an atmosphere of suspicion," and two athletes broke the bottles in an attempt to screw on the lids tight enough to ensure no one could tamper with their samples.

Other flaws in the system, according to the report:

- Athletes say they spent long hours waiting to be tested because multiple athletes had been called for out-of-competition testing and there weren't enough rooms available to take samples.

- Athletes felt therapeutic use exemptions - permission to use banned substances for existing medical conditions - were being abused.

- Athlete support personnel acted aggressively and often tainted the opinions of other athletes in certain areas, sometimes because they were ill-informed about the testing regimen.

The observers said that given the challenges the Sochi scandal brought, there were "generally satisfied with the end-to-end doping control arrangements put in place for the Games."

But Sochi was on almost everyone's mind.

"The trust in the system and the chain of custody of samples was challenged, and the impact of the Sochi experience could not be dissociated from the perceptions of the Olympic athletes toward anti-doping procedures," the report said.