Paul Pogba's brother Mathias has been charged and detained over the alleged extortion of the France and Juventus midfielder.

An investigation was opened last month into allegations Paul was the target of an extortion plot by his brother and childhood friends demanding a 13 million euros ($13 million) sum.

Mathias, who is a free agent after a spell with French fourth-tier side Belfort came to an end in April, threatened to share "explosive revelations" in a video posted on social media.

The 32-year-old has denied taking part in extortion attempts against his brother.

However, it emerged on Saturday that he and four others have been charged and will now be held in jail while he awaits a decision from the judge regarding bail.

Mathias' lawyer confirmed to French outlet BFMTV that his client intends to challenge the decision.

"It's a decision we do not understand especially because the courts have recognized Mr. Pogba did not participate in the acts of kidnapping, which his brother was allegedly the victim of," the lawyer said.

"Mr. Pogba could perfectly have and should have been released during this judicial investigation. So that will not stop there, we will challenge this decision from a legal point of view so that Mr. Pogba can be released as soon as possible.

"This is an individual who has never been talked about, who has a clean criminal record, who is not a thug, who is presumed innocent. And the elements of this file, it is my assessment, show that he did not commit any criminal offense.

"So for a person who may not have, and I'm telling you certainly not, committed a criminal offense, ending up in prison is something extremely difficult. So we are going to fight so that he can get out as soon as possible."