Juventus and France midfielder Paul Pogba's 'B' sample has confirmed the presence of testosterone, a source close to the case told AFP on Friday.

The 30-year-old former Manchester United player, a World Cup winner in 2018, faces a ban of up to four years.

The original test by the Italian anti-doping agency (Nado) showed the presence of testosterone metabolites.

On Friday, Pogba learned that the analysis of his B sample, carried out on the previous day, had produced the same result.

The player's entourage declined to comment.

Under the World Anti-Doping Code, Pogba is liable to a four-year suspension, which could be halved if he proves that he was not at fault.

The ban could even be limited to a few months if the use of the substance took place "out of competition and is not related to his level of performance".

Pogba's representatives said last month that the testosterone came from a food supplement prescribed by a doctor he consulted in the United States.

Testosterone promotes muscle development.

Contacted by AFP, Nado was unable to confirm this information "due to a decision by the Italian privacy authority".

Pogba has seven days to submit his defence to Italy's National Anti-Doping Tribunal, which will investigate his case and request a sanction, a process that could take several weeks.

In addition to the proceedings of the Italian sports justice system, a judicial investigation will be opened by the Turin public prosecutor's office, as doping is a criminal offence in Italy.

Since the announcement of his positive test, Pogba has been unable to train with Juventus, the club to which he returned in July 2022 after six seasons with United.

The announcement came shortly before Juve coach Massimiliano Allegri's press conference on the eve of the Turin derby against Torino, at which he simply said he was "sorry for Paul".

Contacted by AFP, the club, which has also suspended payment of his estimated annual salary of 8 million euros (8.4 million dollars), did not respond.

Pogba started the season attempting to bounce back from string of injuries last season and from summer surgery.

His sample was reportedly taken at his club's opening match of the Serie A season, a win at Udinese on August 20, during which he was an unused substitute.

After the first sample tested positive on September 11,  Pogba's agent Rafaela Pimenta said she was "awaiting the second sample and cannot have an opinion before the results".

"What is certain is that Paul Pogba never wanted to break a rule," she added.