Police in Rotherham tore up paperwork relating to one child sex abuse victim and stopped another from being medically examined, the BBC has been told.
One woman claimed a policeman called her a liar after she reported being abused aged 15, and the other alleges police prevented her being examined after she was abused aged 13.
Both were speaking to BBC Inside Out.
South Yorkshire Police said both cases were now with the police watchdog.
A report in September by Prof Alexis Jay found 1,400 children had been abused in Rotherham between 1997 and 2013 by men of mainly Pakistani heritage.
The abuse they suffered included beatings, rape and trafficking to various towns and cities in England. Carol was living in a children's home in the 1990s when she was taken on occasions by taxi to an Asian restaurant in the town. '
In one incident she was subjected to a violent sexual assault by one of her abusers and was left bleeding.
Carol said: "I told the staff at the children's home and my social worker and they said a police officer was going to to pick me up and take me to a unit.
"The officer that used to come to the children's home [regularly], he came and picked me up in a police car.
"He took me to a lay-by; kept calling me a liar, saying he'd read my files and that I was a liar and no-one was going to believe me, it was more trouble than it was worth and he ripped my paperwork up.
"He dropped me back at an Indian restaurant... back with my abuser."
Lawyer David Greenwood, who is acting for the women in these historical cases, said:
"The evidence that I've seen and the girls that I've spoken to, tell stories that suggest to me that there's something going on at a systematic level, where the police [were] actively preventing cases going forward against these perpetrators."