Marlon Santos has made his switch from Fluminense to Barcelona permanent, according to Brazilian media giants Globo.
The player was on loan at Barça and had already made his debut, but his papers still belonged to the Brazilian club.
His agent, Fred Moraes, has not confirmed the story.
Barcelona will have to satisfy a 6 million euro fee to secure the player, although the actual amount paid may be lower since Fluminense owes the Catalan club some money.
Barça will also avoid paying an upcoming loan fee to Fluminense.
Marlon has played in the Champions League but is currently ineligible to play in either the Copa del Rey or La Liga due to a clerical error.