"The body of this person has been found in a hotel in Seville, there are no signs of violence but we need to wait for the autopsy," she said.
De Villota, daughter of former Formula 1 driver Emilio De Villota, lost her right eye in a serious crash while testing for the Marussia team at Duxford Airfield in Cambridgeshire in 2012.
"Maria has left us. She had to go to the sky like all the angels. I give thanks to God for the extra year and a half he left her with us," read a message from her family posted on De Villota's Facebook page.
The news has shocked the world of motorsport with tributes to a pioneer in women's sport pouring in.
"I am in a state of shock. They have just told me," two-time Formula One champion Fernando Alonso told Spanish sports daily Marca.
"We need to pray for her and be very close to her family. Maria was very loved by all of us and by all of the motorsport family."
President of the Spanish Automobile Federation, Carlos Gracia also added his condolences.
"I have just found out. It is a very hard to take. There is no explanation for what has happened," he told Spanish National Radio.
"She was a great person and an example for everyone."