Former Spanish Formula One test driver Maria de Villota, one of the few women to come close to the top of the sport, but whose career was cut short by a horrific accident last year, has been found dead in a hotel in Seville.
De Villota, who lost her right eye and fractured her skull at a test in England in July last year, had apparently died of "natural" causes, a Spanish police spokeswoman said.
"We are assuming it was a natural death, but we cannot confirm anything," the spokeswoman said, adding that forensic scientists and a homicide unit would examine the scene.
Although the 33-year-old recovered from the life-threatening injuries sustained in the crash, she no longer competed and had instead become an inspirational figure for aspiring female drivers and was due to present a book detailing her experiences on Monday.
The daughter of former F1 racer Emilio de Villota, she was appointed test driver for Anglo-Russian team Marussia a few months before her crash.
She never took part in a general test with other drivers, but was one of only a handful of women to have driven Formula One cars in the last decade.
News of her sudden death stunned Spain and the motor racing world.
"I feel I owe it to her [to say something] because, out of the paddock and out of the motorsport bubble, she was an incredible character and she was a fighter," said Susie Wolff, a Williams development driver who had a test for the team last July and knew De Villota well.
"She had such a spirit for life and what she came through was a testament to her strength of character and her positive outlook," added the Scot from the Japanese Grand Prix in Suzuka.
"After the accident she was so behind me and had such a lust for life. She was so happy to be alive and that she'd survived it, and she had so many great plans for the future."
Spanish F1 driver Fernando Alonso appeared lost for words in an interview with radio broadcaster Cadena Ser shortly after hearing the news.
"I really don't know what to say," he said from Suzuka. "Pray for her and her family and the whole motor sport family. She was really loved by everyone."