Sunnyside police spokesperson Captain Daniel Mavimbela said the victim had planned to buy a hard drive when she agreed to meet the suspect at a fast food outlet on Sunday evening.
She was to meet the man who had reportedly advertised a three-terabyte external hard drive on the internet.
After the meeting, the victim accompanied the suspect to a flat where she woke up naked on a bed about two hours after she had passed out.
“It is believed the vast majority of persons who are victimised after passing out are either spiked or suffocated with carbon tetrachloride or chloroform,” Mavimbela said.
“The woman believes that while she was unconscious, the suspect sexually violated and possibly raped her before abandoning her inside a room in the flat.”
In another incident, Mavimbela said a 19-year-old woman was raped a few weeks before by a man who promised her on social media to put her in touch with “blessers”.
He said due to the heightening of operations, police believed criminals were now resorting more and more to friendlier methods by isolating their potential victims from the public eye through the use of the internet.
Mavimbela added: “Internet users are warned to exercise extreme caution before agreeing to meet strangers. Users are urged to consult widely or insist on meeting strangers at a police station should there be a desire to conclude a transaction that had been initiated through the internet or social media.”