A lawyer for two French international rugby players charged with raping a woman while on tour in Argentina has told AFP he remained convinced of their innocence in a "very painful case for everyone."

Hugo Auradou, 20, and Oscar Jegou, 21, were arrested on July 8, in Buenos Aires, two days after their team played Argentina in the city of Mendoza.

Last Friday, they were charged with aggravated rape of a woman they had met in a bar after the match.

The 39-year-old complainant says she was violently and repeatedly raped by the pair, who insist there was a consensual sexual encounter.

Lawyer Rafael Cuneo Libarona told AFP on Monday he believed the evidence collected so far supports the players' version of events.

Ahead of the first witness testimony in the case set to be heard Tuesday, Libarona said the pair were being well treated at a detention center and Argentine "justice is working very well."

 Q: Are you confident in the case?

 "More and more, because new evidence is coming out, every day videos and images come out and technology is allowing us to... construct a very strong element of innocence.

"I have no doubt that the defendants did not commit the crime, no doubt."

Libarona added this was "a very painful case for everyone: for the two Frenchmen -- because in my opinion they are innocent -- and for the victim -- because in her opinion she was the victim of a crime.

"So we have to be respectful towards everyone."

 Q: Will you seek their transfer to house arrest ahead of the pre-trial custody hearing?

 "Our priority is to obtain house arrest... to protect (their) physical integrity and morale, nothing more.

"In cases involving sexual (crimes) and foreigners who do not speak Spanish, this requires protection of the accused."

The case will continue whether the men are in jail or under house arrest, added the lawyer: "there is no risk of escape and... no obstruction of the investigation."

 Q: How are the players' families taking it?

 A: "Certainly, she is worried," Libarona said of Auradou's mother, who he had met earlier.

"If I had my child in these conditions, I would be very concerned. Despite their innocence, it doesn’t alleviate the worry.

"France is worried about this. Rugby is worried. I am worried.... We will work with the utmost seriousness to prove their innocence."