MONTREAL (AFP) - The World Anti-Doping Agency (Wada) has recorded 99 positive tests for the newly banned drug at the centre of the Maria Sharapova case, officials said on Friday.

A spokesman for Wada said the agency had recorded nearly 100 positive tests for the endurance-boosting substance meldonium since it became outlawed on Jan 1.

"We can confirm that since Jan 1 2016, when the substance meldonium became banned, there have been 99 adverse analytical findings for meldonium recorded," Wada spokesman Ben Nichols said in an e-mail.

Russian tennis star Sharapova confirmed on Monday she had failed a test for the drug at the Australian Open in January, claiming it was an honest mistake.

The case has triggered intense interest in meldonium, a hitherto little-known substance which is available as an over-the-counter medication in many parts of Eastern Europe but not approved for use in the United States by the Food and Drug Administration.

Wada did not name the athletes involved in the 99 cases since the start of the year.

However, a lengthening list of athletes had already been identified as testing positive, with Russian biathlete Eduard Latypov becoming the latest to be caught using the drug at an event in February.

Swedish runner Abeba Aregawi tested positive in February, while 2015 Tokyo marathon champion Endeshaw Negesse, Ukrainian biathletes Olga Abramova and Artem Tyschcenko and Russian ice dancer Ekaterina Bobrova have also been caught.

Meldonium is used to treat ischemia, a lack of blood flow to parts of the body.

The drug is manufactured in Latvia and prescribed to treat heart disease.

The increase in blood flow it produces could improve endurance and recovery time after exercise and Wada moved it from the "monitored" to the "prohibited" drugs list "because of evidence of its use by athletes with the intention of enhancing performance," the anti-doping body has said.