But the state needs to launch a formal application to gain access to the device and its data.
The state prosecutor told the Pretoria magistrate's court the suspect's cellphone is critical.
Ninow made his second appearance in court on Tuesday.
He faces charges of rape, drug possession and assault with intent to do grievous bodily harm.
Footage of Ninow at the location was leaked online.
It shows Ninow, naked and bleeding, shouting at other patrons.
Ninow was apprehended at the restaurant, treated for injuries and taken into police custody.
His attorney has told the court Ninow may have sustained further injuries.
Nino has not applied for bail and remains in police custody until his next court appearance on 1 November.