Russia's top sports scientists have developed a replacement for the banned performance-enhancing drug meldonium.

Vladimir Uiba, head of Russia's Federal Micro-Biological Agency (FMBA) told the TASS news agency on Wednesday that the new drug was “more effective by far” than the original.”

Meldonium was classed as a banned substance for athletes by the World Anti-Doping Agency (WADA) in January 2016. More than 100 Russian athletes were tested positive for the drug after the ban, including tennis superstar Maria Sharapova.

The drug, which was first developed in 1970, expands the arteries. WADA has argued that the increased blood flow could give athletes an unfair advantage by boosting the amount of oxygen flowing throughout the body.

The claim is disputed by a number of people and organizations, including the drug's manufacturers.