The Russian Anti-Doping Agency (RUSADA) told the country's National Federations about the impending banning of meldonium in good time, a leading sports official has claimed.
Alexander Kravtsov, head of the Russian National Teams' Traning Centre, said that it would have been up to doctors to pass on the news to athletes.
The heart attack drug has become a buzz word in sport due to a spate of failures by top names since it was outlawed by the World Anti-Doping Agency (WADA) on January 1.
Many of those to test positive are Russians with quadruple world champion swimmer Yuliya Efimova - one of the most high-profile athletes to fail - claiming yesterday she was not told meldonium was to be banned.
Others, including five-time Grand Slam tennis champion Maria Sharapova, admitted receiving correspondence which they said had not been read.
Kravtsov denied any suggestion that RUSADA has not informed athletes.
He appeared to hint, however, that any breakdown in communication could have been down to the doctors.
"RUSADA had officially and timely notified doctors of all sports federations that meldonium would be on the list of banned substances starting January 1," he told Russian news agency TASS.
"Considering their official status, they [the doctors] had to pass on this information to their teams."
Twenty-three-year-old breaststroke swimmer Efimova, who also has an Olympic bronze medal to her name, is facing a lengthy ban as the meldonium failure was her second positive drugs test.
She served a 16-month ban for doping having failed for banned steroid DHEA in 2013 but has claimed, as others have, that she took meldonium for health reasons.
"I have not received any notifications that meldonium will be included in the list of banned substances from 1 January 2016, not even one," she said to Russian TV channel Rossiya 24 yesterday while protesting innocence.
"Neither from Russian nor from international organisations.
"Neither in the electronic form nor verbally."
More than 100 athletes have failed for meldonium so far.
The drug was only added to the banned list after WADA said it was being used for performance enhancing purposes.
There are claims it was given to Soviet Union soldiers during the Afghanistan War in the 1980s in order to boost endurance.
The makers of the Latvian drug have suggested that sometimes it can take "months" to leave a person's system.
This could back-up claims made by athletes who say they stopped taking meldonium ahead of January 1 but still tested positive afterwards.