His Twitter feed was followed by official professional tennis organisations. Getty Images

A Twitter user pretending to be a rising tennis star managed to trick the BBC, Serena Williams and Martina Navratilova into believing a made-up story about him overcoming adversity which Williams described as "inspiring".

Darko Grncarov from Macedonia pretended to be a player who suffered a stroke two days before his first match as a professional, leading to interviews with the Metro newspaper and a nine-minute slot on BBC radio.

One reporter however decided to investigate, and outed Grncarov as a fraud after noticing a number of Twitter accounts repeatedly tweeting about the player who had only been listed for one international match. He reported his findings on Slate.

Grncarov, 20, found attention on social media after saying (while appearing to be a pro) that he would have taken a stance against homophobic and transphobic remarks made by Margaret Court, alongside tennis legends Billie Jean King and Martina Navratilova.

King and Navratilova said they would have refused to play at the arena named after Court, but no active players joined them. Grncarov appeared to be someone who would.

Grncarov is a real person who does, or did genuinely play tennis at one time. Local news outlets reported on success at a junior tournament in 2014, but no evidence of such an event could be found and the players he was meant to have played were not at the event.

He appeared on television too to discuss his "success".

Stories continued to circulate for years until the summer of 2017, when some 200 fake Twitter accounts appeared dedicated to Grncarov, tweeting about a variety of topics from his apparent crush on pop star Nicole Scherzinger to an apparent net worth of $1.5 million.

"This army of Twitter users also worked in concert to badger prominent Twitter accounts, including @ATPWorldTour and @ITF_Tennis, into following the Macedonian tennis player," Slate reports.

The accounts also pushed for Grncarov to appear on The Ellen Degeneres Show and attacked those who cast doubt on his story.

In July 2017 Grncarov's account tweeted the aforementioned story. "After a long year of trying and believing, right now I am stronger than before my stroke," he wrote. "I am no Roger or Novak but I am happy for being offered places at big tournaments as a comeback support."

It was this story that caught the attention of Serena Williams.

His fame drew the attention of the media and online he had 15,000 Twitter followers and more than 41,000 on Instagram.

He appeared on BBC Five Live in January, introduced by host Dotun Adebayo as "a young Macedonian player aiming to join the ATP Tour soon who said he will boycott [Margaret Court Arena] if he gets the chance".

"The thing is that I simply cannot respect someone who has offended so, so many people, and what she did was simply disgusting and not human at all," Grncarov told the BBC.

Slate's Ben Rothenberg exchanged messages with Grncarov, but the Macedonian ended the conversation and blocked him after he laid out his accusations. Grncarov then deactivated his Twitter, Instagram and Facebook accounts. Many of his supporting accounts were also deactivated.