Shakira, a Colombian singer, is facing an eight-year sentence after being found guilty of a €14.5 million (£3.8 million) tax fraud.
The prosecutor's office made a settlement offer to end the case earlier this week, but the singer rejected it.
Shakira claims she did not reside in Spain between 2012 and 2014, although she is accused of neglecting to pay taxes during that time.
According to the prosecutor's dossier, which Reuters has access to, Shakira usually lived in Spain between 2012 and 2014.
Shakira purchased a home in Barcelona in May 2012 and made it her residence.
The paper demanded an eight-year prison term and a fine of more than €23 million if she were proven guilty.
Shakira's agents cited a statement from Wednesday that said the singer was "certain of her innocence."
The Spanish tax agency claimed the 45-year-old singer owed €17.2 million in taxes, which she claimed to have already paid.
The development came a month after Shakira and her husband, the FC Barcelona defender Gerard Piqué, announced their separation.