Ukraine's National Anti-Doping Centre (NADC) had athletes make appointments for unannounced tests and warned others of when they would be tested, according to a World Anti-Doping Agency (WADA) independent investigation released on Tuesday.
The investigation code named 'Operation Hercules' and launched in 2019 uncovered evidence the NADC had given advance warning to athletes of tests going as far back as 2012.
"Operation Hercules has raised serious questions about the integrity of NADC’s testing practices, and the competence of some staff," WADA Intelligence and Investigations Director Gunter Younger said in a statement.
"Moreover, the apparent longevity and brazenness of these practices suggests significant organizational failings within NADC.
"Operation Hercules has convincing and corroborated evidence that NADC was engaged in the practice of telephoning athletes or contacting them through their coaches to request their attendance at the NADC, the following day, for testing.
"The evidence suggests that NADC would adopt this practice often before important international events and there were times when an entire discipline of the national team was present at the NADC awaiting testing.”
The report also said it found evidence that in 2021 the NADC reported at least six in-competition tests as out-of-competition samples.
The samples were deliberately misreported for the purposes of meeting the minimum number of out-of-competition tests required from an athlete to compete at this year's Tokyo Olympics.
WADA said the samples in question were analysed and returned negative.
The findings will be handed over to the Compliance Review Committee which will make recommendations to the WADA executive committee on whether the NADC should be ruled non-compliant.
If the NADC is found to be in violation of the WADA Code and non-compliant then Ukraine could risk being banned from competing at next year's Beijing Winter Olympics.