Ukrainian rising star Dayana Yastremska has been provisionally suspended from all tennis activity following a positive doping test.

A urine sample given by the 20-year-old, ranked 29th in the world, in an out-of-competition test on November 24 was found to contain a metabolite of mesterolone, a synthetic testosterone.

In a statement on Twitter, Yastremska denied committing an offence, saying: "I firmly state that I have never used any performance enhancing drugs or any prohibited substances.

"I am astonished and under shock, particularly given that two weeks prior to this test I tested negative at the WTA event in Linz.

Dayana Yastremska has been provisionally suspended from all tennis activity

"Only a very low concentration of mesterolone metabolite was detected in my urine. Given that low concentration and given my negative test two weeks earlier, I have received scientific advice that the result is consistent with some form of contamination event.

"Due to the confidentiality of the proceedings, you will understand that I am not able to share any further information at this stage. However, I am currently working with my team and you can be assured that I am resolutely determined to do everything to clear my name."

Mesterolone is a non-specified substance, meaning a positive test carries a mandatory provisional suspension.

The tennis star said she was "astonished and under shock" following the news

Yastremska was charged with an anti-doping rule violation on December 22 and the provisional suspension takes effect from January 7.

The Ukrainian chose not to challenge the provisional suspension. A full hearing into the case will take place at a later date.

Yastremska has won three WTA titles, the first two when she was only 18, and reached the fourth round of Wimbledon in 2019.

Six months ago, she was embroiled in controversy after posting a controversial blackface picture to her social media.

Six months ago she posted a controversial blackface picture to her social media

Amid the anti-racist demonstrations and Black Lives Matters protests that have taken place across the world following the death of George Floyd in May, Yastremska attempted to insert herself into the debate by posting four images of herself with one half of her body black and the other white.

Within minutes, Yastremska was widely condemned for the post and she soon deleted the posts on Twitter and Instagram.

Yastremska, however, defended the controversial snaps and claimed she was "misunderstood".

"Earlier today I posted pictures that I thought would spread a message of equality," Yastremska said in a statement on social media back in July. "It clearly did not and has been misunderstood.

"I have been warned about the negative impact but I did not - and still don't - consider it as blackface.

"I did not intend to caricature but to share my feelings about the current situation: we should all be treated as equal.

"I am so disappointed that my message has been corrupted: these pictures divided people when they were meant to unite. That's why I deleted them.

"I sincerely apologise to all the people I have offended. I truly had only good intentions."