Ukraine’s former European indoor 800m champion Nataliya Lupu tested positive for meldonium – a banned substance used by athletes. She won’t be able to participate in this week’s world indoor championships in Portland tomorrow.

The move came after the World Anti-Doping Agency(WADA) expressed concern over meldonium’s use.  On the federations site, Lupu said that she used the drug for 15 years as a medical prescription “due to changes in her cardiogram”. However, she stopped taking the drug in November, before it was banned on January 1.

In addition 19 other athletes, four are Olympic medallists, were also tested positive for meldonium.

In 2014, Lupu tested positive for the stimulant, methylhexaneamine. She was banned from the 2014 world indoors in Sopot, Poland.  Last week, tennis player Maria Sharapova also tested positive for meldonium in the Australian Open. In a press conference, she admitted that she used the drug for medical purposes.

For this year’s Rio Games, International Olympic Committee [IOC] said that it will re-analyse the samples collected at the 2008 Beijing and 2012 London Olympics, according to The Sydney Morning Herald.

“The aim of the [re-testing] programme is to prevent athletes, who cheated in London or Beijing and got away with it because we didn’t have as advanced methods of analysis as we do now, from competing in Rio de Janeiro,” said IOC medical director Richard Budgett.

“The results will come in a number of weeks or months.”

Meldonium is a popular drug common in Soviet countries. It boosts the blood flow and enhances performance. It was widely used by athletes before the ban.

Last week, WADA reported 99 positive cases of meldonium after the ban.“I can confirm that since 1 January 2016 when the substance Meldonium became banned, there have been 99 adverse analytical findings for Meldonium recorded,”  said WADA spokesman Ben Nichols said in a report by Newsweek.

“These cases were analyzed by a number of different WADA-accredited laboratories and reported by many different NADOs [national anti-doping organizations] and international sports federations.”