Mathias Pogba's lawyer, Richard Arbib, said in a statement that his client wants "to state emphatically that he is a complete stranger to any extortion attempt against his brother, Paul Pogba."
Two judges were appointed last week to investigate allegations that the World Cup winner was targeted by his brother and childhood friends. Arbib insisted that Mathias Pogba wants "more than anything else" to ease the situation with his brother.
The Paris prosecutor's office opened an investigation last month into attempted organised extortion, which is being handled by anti-corruption police.
French authorities are investigating allegations that Pogba was the target of an extortion plot by his brother and childhood friends who demanded €13 million ($13m) from the former Manchester United player.
When the group approached Pogba about their demand at the Juventus training center in Turin, he said his brother Mathias Pogba was among them, according to France-Info radio.
The case became public after Mathias Pogba posted a video and tweets threatening to share "explosive revelations'' about his brother and France star Kylian Mbappe.
Paul Pogba reportedly told investigators the blackmailers aimed to discredit him by claiming he asked a witch doctor to cast a spell on Mbappe.
Pogba denied that allegation and Mbappe has sided with the player he won a World Cup with in 2018.
"He called me, he gave his version of the facts,'' Mbappe said Monday. "It's his word against the word of his brother. He [Paul Pogba] already has certain problems and I think it's not the time to add to them for him. We'll see how that all goes, I'm pretty detached from all that.''
French officials have said Pogba paid €100,000 (nearly $100,000) to the group that tried to extort millions more.
Pogba reportedly made the payment after he was threatened by masked, armed men in a Paris apartment in March while he was in France for a national team game.
The 32-year-old Mathias Pogba is also a football player who spent most of his career with lower-tier teams in England and other European countries.