Hundreds of attempts to carry out drug tests on Russian athletes this year have been thwarted, the World Anti-Doping Agency (WADA) said Wednesday, in a bombshell report issued just days before a key decision on the country's participation at the Olympic Games. Drug testers had faced intimidation and threats from armed Russian security forces while athletes continued to evade doping control officers with a variety of techniques. The report comes just two days before the International Association of Athletics Federations (IAAF) meets in Vienna to decide whether Russian athletes should be allowed to participate in the Rio de Janeiro Olympics. But the explosive revelations in the WADA summary will raise fresh questions about Russia's repeated vows to clean up its drug-tainted sporting culture in time. The WADA summary said more than 736 tests between February 15 and May 29 were declined or cancelled for a variety of reasons ranging from sample collection or athlete whereabouts. Testers reported receiving hostile treatment when attempting to carry out drug tests in military cities, including intimidation and threats of expulsion from the country. Military cities are often given as a place of residence by athletes seeking to avoid drug testers because of the difficulty in gaining access to the areas, the report said. On other occasions, Russian coaches, doctors and venue staff had insisted on taking photographs of doping control officers' accreditation cards and paperwork. Other passages of the report highlighted the darkly comical lengths drug cheats would go to in an effort to avoid detection. One track and field athlete had been caught trying to provide a urine sample using a container inserted into her body. "When she tried to use the container it leaked onto the floor and not into the collection vessel," the report stated. The athlete subsequently threw away the container and then attempted to bribe the doping control officer. Other examples of obstruction occurred during an athletics event. One athlete was seen running away from a mixed zone in an effort to avoid being taken to doping control by a chaperone. Another athlete exited a stadium during a race and subsequently could not be found, the report said. At the Russian National Walking Championship on Feb. 27, 15 athletes mysteriously did not start, withdrew or were disqualified, the report said. Two cyclists meanwhile came to the attention of drug testers after it was discovered they had not been seen at their stated "whereabouts location" for more than a year. When they were cited for missed tests, they both retired. In another incident, the entire Russian under-18 team at the Ice Hockey World Championships were withdrawn en bloc and replaced by the under-17 team, reportedly due to use of the banned drug meldonium. Meldonium, the drug which led to the recent tennis ban for Russian star Maria Sharapova, was involved in 49 of 52 doping cases logged between February 15 and May 29. Meanwhile at a Russian national wrestling championship, there had been reports of a "laboratory" equipped with its own "centrifuge and other analytical equipment," WADA said. The WADA report, which was compiled with the help of UK Anti-Doping, whose testers went into Russia, provides further ammunition for critics who have called for the IAAF to issue an Olympic ban when it meets this week. The IAAF suspended Russia from competition in November after an earlier WADA report which detailed a systematic doping program and corruption by sports officials. IAAF President Sebastian Coe has said the ban will only be lifted if there is clear evidence of a "verifiable change both in anti-doping practice and culture." In its bid to overturn the ban, Russia has announced a raft of reforms including the introduction of compulsory anti-doping classes in schools to reform attitudes toward the use of performance-enhancing drugs. Russia's anti-doping agency RUSADA will develop a special curriculum, based on WADA guidelines, for the 3,000 sports schools where the country's elite athletes train.