Ituma, who had Nigerian roots, was 18 years old.
She was in Turkey for a Champions League match with her team Igor Gorgonzola Novara, sources at the club and the Italian volleyball federation said on Thursday.
Istanbul police have immediate begun investigations after carrying out an autopsy.
The news has left the volleyball world in shock.
“Only those who truly knew her know how fragile she was,” said ex-teammate Stella Nervini on social media.
“To die at 18 is unnatural,” said Marco Mencarelli, Ituma’s coach.
President of the Italian Volleyball Federation, Giuseppe Manfredi, spoke of how heartbroken the volleyball community is.
“We’re all dismayed by this tragedy that’s hit not only the volleyball world, but all of Italian sport,” he said.
“We cry for the loss of not only a great talent, but above all a marvellous girl who we watched grow.
“It’s an immense tragedy that none of us could have prepared for.”
ANSA
