Ronaldinho and Assis travelled to Paraguay on March 4 to participate in a children's charity event and promote a new book. The pair were arrested later that day when authorities realised they had entered the country with fake passports.
It is reported that Paraguayan officials have ordered that the prison on the outskirts of capital Asuncion tighten protocols to prevent the spread of the virus.
The two-time world player of the year and his brother Roberto, who was detained with him, spent their third night behind bars in the capital Asuncion on Sunday after using forged travel documents to enter the country.
Ronaldinho's lawyer had earlier denied that he and his brother had used fake passports to enter Paraguay.
Ronaldinho and his brother, Roberto de Assis, were detained on Wednesday after police raided their presidential suite at a luxury hotel in Asuncion
