Inside the doping deal for tennis' world number one

He has won the past two Grand Slams - but less than a month after his Australian Open victory Jannik Sinner is the talk of tennis, after agreeing a doping deal which has seen him banned for three months.

The timing means the men's world number one will be back for the next major - the French Open. Convenient, critics say.

The controversial agreement between the Italian's legal team and the World Anti-Doping Agency (Wada) officials has prompted accusations of favouritism and led to some players questioning their faith in clean sport.

But what really happened behind the scenes? And what impact might this case have on anti-doping?

BBC Sport has spoken to key figures involved to establish the inside story - from the timing of the ban being "compelling" to the "struggle" of convincing Sinner to bear any ban at all when it was accepted he did not intend to cheat.

Little over a week ago, Sinner was practising in Doha as he prepared to play in the Qatar Open.

But he knew things might change quickly.

Behind the scenes there were discussions that would rule him out of that tournament - and the next few months on tour.

In what ended up being a "late night" on 14 February, Sinner's lawyer Jamie Singer was deep in phone calls with Wada's most senior lawyer.

Then, early the following morning, the surprise news emerged that the three-time Grand Slam champion had accepted an immediate three-month ban.

Sinner and Wada announced they had "entered into a case resolution agreement" over his two failed drugs tests last March.

This is a special mechanism that has been in place for the past four years and allows deals to be agreed to conclude doping cases.

"It all happened unbelievably quickly," Singer told BBC Sport. "In a matter of a couple of days, really."

How do you persuade the world number one player to accept a ban for something he believes he is innocent of?

That was the challenge facing Sinner's team.

To understand the extent of that we have to rewind to August when an independent tribunal cleared him of wrongdoing.

It accepted Sinner's explanation that traces of clostebol - a banned anabolic steroid - had entered his system through inadvertent contamination from his physio during a massage.

Wada, while not challenging the tribunal's overall decision, appealed against the 's ruling that Sinner "bore no fault or negligence".

However, this would have carried a ban of "one to two years" at the Court of Arbitration for Sport (Cas).

Although Wada initially called for this punishment publicly, eventually its officials came to feel this would not be the right outcome.

With time ticking before the Cas hearing in April, Wada made two approaches to Sinner's team for the case resolution agreement.

The first attempt was rebuffed as Sinner's team wanted to submit the full defence case first.

That was handed over on 31 January, and in early February the first "concrete discussions" began after the second approach.

But with Sinner always sure of his innocence and confident he would face no ban, would he accept a three-month suspension?

His lawyer Singer said it was "quite tricky" to convince Sinner to take the offer.

"When I was saying 'well, look, maybe we should settle for three months', he was saying 'well, why would we do that if the first independent tribunal found it was no ban at all, why would I accept three months now">