Reedie said the drug, which Russian tennis player Maria Sharapova told a news conference she had used for health reasons after she failed a drugs test earlier this year, was responsible for 47 of the 49 adverse analytical findings in Russia between November 2015 and May 2016.
Meldonium, a Latvian drug which helps to adjust the body's use of energy and can boost stamina and aid endurance, was added to WADA's list of banned substances at the start of this year.
Since then, Russians from several sports, including rugby sevens, biathlon, speed skating, volleyball and athletics, have returned positive tests for the drug.
“This drug is not licensed for Europe, not licensed for the United States. It doesn’t fit within our systems. Clearly it is an issue,” Reedie said in a wide-ranging interview with insidethegames website.
WADA said last month that doubts over how long meldonium stayed in the body meant athletes who had tested positive for it before March 1 could have their bans overturned.
Reedie said the WADA task force investigating Russian drug use was arranging to meet the former Sochi Olympic laboratory director Grigory Rodchenkov, who alleged in a recent interview that Russian authorities were involved in a cover-up in which samples were switched to avoid dozens of their athletes being exposed as drug cheats at the 2014 Winter Games.
