[caption id="attachment_15839" align="alignnone" width="580"]Maria Sharapova banned for two years. File Pic Maria Sharapova banned for two years. File Pic[/caption] Internet Desk: Maria Sharapova has been banned for two years by the International Tennis Federation for using a prohibited drug. The Russian was provisionally banned in March after testing positive for meldonium at January's Australian Open. The heart disease drug, which 29-year-old Sharapova says she has been taking since 2006 for health issues, became a banned substance on 1 January 2016. The five-time Grand Slam winner said she "cannot accept" the "unfairly harsh" ban - and will appeal. Sharapova will now challenge the suspension, which is backdated to 26 January 2016, at the Court of Arbitration for Sport (Cas) Sharapova became the first Russian to win Wimbledon as a 17-year-old in 2004, added the US Open in 2006 and the Australian Open in 2008, before completing a career Grand Slam with the French Open title in 2012. She won the French again in 2014 and was Forbes' highest-earning female athlete in the world for 11 consecutive years until Serena Williams claimed top spot this year. The World Anti-Doping Agency (Wada) said in April that scientists were unsure how long meldonium stayed in the system, and suggested athletes who tested positive before 1 March could avoid bans, provided they had stopped taking it before 1 January. However, Sharapova had already admitted she continued taking the substance past that date, saying she was unaware it had been added to the banned list as she knew it by another name - mildronate. The London 2012 Olympic silver medallist added: "I have missed playing tennis and I have missed my amazing fans... your love and support has gotten me through these tough days. I intend to stand for what I believe is right and that's why I will fight to be back on the tennis court as soon as possible."