The alleged accuser told Spanish media that Alves reached underneath her underwear without consent while in a nightclub in the city at the end of December.
The veteran right back was arrested on Friday morning and taken to the Ciutat de la Justicia in Barcelona where the Spanish justice system will decide on his provisional situation as investigation continues.
Catalonia’s Supreme Court confirmed that it has opened proceedings "for an alleged crime of sexual assault as a result of the complaint filed by a woman for events that allegedly occurred in a nightclub in Barcelona last month."
A spokesman for the regional Mossos D’Esquadra confirmed: “A man accused of an indecent assault at a nightclub in Barcelona late last year has been arrested. He has now been taken to court after making a statement to police. It will be up to the court now to decide what measures to take.”
Earlier this month, Alves denied the allegations when asked by Spanish TV channel Antena 3.
He admitted he was at the night club with his friends but denied knowledge of the woman.
"I was dancing and having a good time without invading anyone's space," he said.
"I don't know who this lady is. How could I do that to a woman? No."