The World Anti-Doping Agency (WADA) has extended the period during which athletes may escape punishment if they have tested positive for meldonium from March 1 to September 30.
Under new guidance, athletes who provided a urine sample which returned a positive test for the heart-attack drug between January 1 and February 29 can also be given a “no fault” verdict if their sample contained less than five micrograms of meldonium.
This marks an increase from the previous set of guidelines published by WADA, which stated if below one microgram of meldonium was detected and the failed test came before March 1, a negligence or no fault verdict could be reached.
The news could lead to more athletes who have tested positive for the drug, manufactured in Latvia, avoiding a suspension from their respective sport.
WADA published a clarification on meldonium in April, which gave hope to many who are currently provisionally suspended ahead of the Olympic Games in Rio de Janeiro next month.
It led to criticism of the organisation, with many claiming they had poorly handled the situation concerning the drug.
One prominent critic was Russian Sports Minister Vitaly Mutko, who branded meldonium a "trap drug" and blamed WADA for a lack of research.
The development comes after WADA received the results of their first urinary excretion study surrounding meldonium which came as a result of confusion over how long the substance stays in the body.
"Typically, WADA does not commission excretion studies for substances that are added to the List as the Agency is generally able to rely on this information being provided by the manufacturer or regulatory authorities," a statement published today read.
"In the case of meldonium, however, no information relating to urinary excretion was available and so once it was added to the List, WADA undertook excretion studies."
WADA President Sir Craig Reedie added: "We are pleased that the necessary urinary excretion studies have now progressed; and that, the guidance we are now able to provide our stakeholders to help them manage meldonium cases is clear and scientifically robust."
A number of top athletes across several sports have failed for meldonium, including Russia’s five-time Grand Slam winning Maria Sharapova, who is currently serving a two-year ban, and four-time world swimming champion Yulia Efimova.
Efimova had her provisional suspension for meldonium lifted in May.
“The addition of meldonium to the Prohibited List created an unprecedented situation and therefore, during a transitional period, it warranted additional guidance for those in the anti-doping community tasked with managing cases,” WADA’s new director general Olivier Niggli said.
“We place full trust in the ability of our stakeholders to manage meldonium cases effectively, and will be on hand to assist them as necessary.”
WADA added meldonium, which was developed in Latvia, to the banned list on January 1 after claiming there was evidence that it was being used for performance enhancing purposes.
There are claims it was given to Soviet Union soldiers during the Afghanistan War in the 1980s in order to boost endurance.
Many of those to have taken it, however, say they did so for medical reasons, while others claimed that they were not aware it had been banned.