The European Boxing Union (EBU) light-heavyweight champion failed a drugs test on March 12 following his unanimous points victory over Frenchman Patrick Bois in Paris.

Mikhalkin has been stripped of the belt he successfully defended three times, according to the EBU.

Meldonium was added to the World Anti-Doping Agency's banned list on January 1.

Since then more than 130 athletes have tested positive for the drug, originally developed in Latvia to treat patients with heart problems.

Russian Sports Minister Vitaly Mutko warned last month that as many as 30 athletes from the country may have tested positive for the drug.

Mikhalkin's failed test brings the total number of Russians known to have tested positive to 30, 28 of whom have been identified publicly, including former Wimbledon champion Maria Sharapova and four-time world swimming gold medallist Yuliya Yeifmova.

They come from 18 different sports and disciplines.

The figure does not include Russia's junior ice hockey squad.

They were withdrawn from the International Ice Hockey Federation Under-18 World Championships last week following reports in the country that the whole squad has been changed due to several players testing positive for meldonium.

The EBU's general secretary Enza Merchionne Jacoponi said: "Igor Mikhalkin tested positive for an illegal substance last month and, in accordance with the rules of the EBU, he was stripped of his belt.

"The illegal substance in question was meldonium, which is now on WADA's banned list but was not on the list until January of this year.

"We asked him if he had taken the drug, and he confirmed it.

"That is why no counter-analysis of a B-sample has taken place."

Mikhalkin, who had won 18 of his 19 professional fights, admitted taking the drug but claimed he had stopped taking it two weeks before his fight.

"It is true that I have recently taken meldonium," he told WorldBoxingNews.

"Until a few months ago that was allowed, and absolutely consistently in Russia.

"I did not realize that it is now forbidden. 

"I had stopped it anyway, but apparently it takes a long time until it is completely degraded from the body.

"I have made a mistake, and I'm very sorry.

"I stand for a clean sport and will never again take any medication without checking several times before that everything is in order."

List of Russians known to have tested positive for meldonium: