Maria Sharapova is only the latest example of an endorsement gone wrong. Brands never believe that the worst might happen
COMMENT: The Russian's PR team may have won the opening exchanges but there are still many questions to answer
Sharapova claims she was prescribed Meldonium in 2006 after being diagnosed with early signs of diabetes, heart irregularities and a magnesium deficiency
'It’s a big concern because it’s clear that people are abusing the drug'
Sharapova has been legally taking meldonium for the past decade, but a Wada rule change banned the substance at the start of this year
Sharapova revealed that she failed a drug test after taking meldonium over the course of the last decade, with the substance outlawed at the start of this year
Porsche have followed Nike and Tag Heuer in suspending their sponsorship of Sharapova after her failed drug test revelation
Russian Tennis Federation president Shamil Tarpishchev says he expects Sharapova to compete at Rio 2016 despite failing a drug test
Sharapova held a press conference on Monday to reveal that she tested positive for the banned substance meldonium during the Australian Open in January
Sharapova revealed she failed a drug test after taking meldonium since she was 16
Sharapova revealed on Monday that she failed a drug test at the Australian Open, with the ITF provisionally suspending her
Sharapova accepts "full responsiblilty" for testing positive for the banned substance at the Australian Open in January
The Russian delivered the shocking revelation in a press conference at a hotel in Los Angeles
A look at the career of Maria Sharapova on and off the court ahead of her 'major announcement'
Sharapova will speak at 20:00 GMT on Monday after calling a surprise press conference