"Fear of being racist doesn't stop them stopping and searching black youths in far greater numbers than their white counterparts."
I don't think it was so much "fear of being racist" per se--I think it was more a kind of worry that if the racially slanted nature of the case became apparent, then things in Rotherham and other northern towns might "kick off." At the very best, heightened ethnic tensions, and at the worse, race riots.
So you get vague messages to "be discreet" "smooth things over" "don't say things that may start a bunfight" etc. Somewhere along the line, the cases get shelved or forgotten about, and the victims fall between the cracks. I have seen this kind of thing happen before.
We have already had race rights in some northern and midlands towns connected with tensions between white and Mirpuri residents, so concern that dragging the case into the open might cause an explosion was, in some ways, not an unreasonable thing for the police to assume. It might well happen now that the case has finally come to light. There is a lot of barely suppressed rage in Rotherham right now.