Barcelona coach Xavi Hernandez apologised Sunday for a comment he had made about Dani Alves, who was arrested earlier this week following sexual assault allegations.

The 39-year-old defender, sacked by his Mexican club Pumas after his arrest, is being held in custody without bail in Barcelona.

The charge of sexual assault in Spain can mean anything from unsolicited and unwanted sexual groping to rape.

While police declined to give details on the case, a source close to the investigation told AFP that Alves is accused by a woman of rape.

Xavi had said Saturday he was in a state of shock after learning of the allegations and arrest, but also that he "felt bad" for Alves, while not mentioning the alleged victim.

"Yesterday what I wanted to say about Dani Alves was misinterpreted, perhaps I was not forceful enough with my words and it is important that I explain myself," said Xavi on Sunday after Barcelona's 1-0 win over Getafe in La Liga.

"It is a very lurid subject and yesterday I forgot to talk about the victims. It wasn't an appropriate comment.

"All actions of this type must be condemned, whether Dani or anyone else did it. I apologise to the victim, to the victims of both gender violence and this type of violation."

Alves, who played for Barcelona for eight seasons between 2008-2016, rejoined the Catalans for a short spell last season under his former team-mate Xavi.

Catalonian police said they received a complaint on January 2 from a woman who accused Alves of sexual assault.

The alleged sexual assault took place at a popular Barcelona nightclub overnight December 30-31, according to Spanish media reports.

Alves was a key player in Barcelona's golden era, winning three Champions League trophies with the club, and six La Liga titles.

The Brazilian also played for Sevilla, Paris Saint-Germain and Juventus among other sides.