MOSCOW — Coming to the defense of Maria Sharapova and others caught using meldonium, Russian Foreign Minister Sergei Lavrov said Thursday the drug never should have been banned.

Lavrov, echoing comments made by the inventor of the drug, said it was “a very strange decision, according to expert opinion” to put meldonium on the list of banned substances.

“In recent days there has been no limit at all to comments from specialists, including the inventor of this substance,” Lavrov told Russia’s Ren TV. “They clearly and professionally explain that it isn’t doping at all but a normal method for supporting the body and its basic functions.”

Meldonium, a blood-flow drug that historically was used to improve Soviet soldiers’ endurance, was banned as of Jan. 1.

On Monday, Sharapova said she had tested positive for the drug at the Australian Open.

Despite her positive test and suspension from playing tennis, Sharapova thanked her fans on Wednesday in a Facebook post.

“I woke up yesterday morning with an inbox, in full capacity of love and compassion,” Sharapova wrote. “On average, I love the mornings. New day, new start. It is fair to say that this day was not average. Nothing came to mind at 6am, except that I am determined to play tennis again and I hope I will have the chance to do so.”

The World Anti-Doping Agency said meldonium was banned because there was evidence it enhanced performance and was being widely used in sports.

Lavrov, however, demanded that WADA present more evidence to prove that meldonium did enhance performance while suggesting the drug’s Soviet origins could have led to prejudice against the substance.

“The recent situation raises a lot of questions when a flurry of bans and accusations has been aimed at our leading, great athletes,” he said.

A study published Wednesday in the British Journal of Sports Medicine found that up to 490 athletes may have been taking meldonium during last year’s European Games in Baku, Azerbaijan. The drug was not banned at that time.