Greater Manchester Police have admitted: "We need to be both realistic and frank that as [Sir Cyril] Smith is no longer alive, we will not be able to bring any criminal prosecution against him."
But the force is continuing to encourage anyone who believes they were a victim to contact them:
I would stress that if you do want to speak to someone, your information will be treated with the appropriate sensitivity and in total confidence
If we receive any evidence that anyone was complicit in the abuse that is still alive today, we will of course investigate that thoroughly.
Lastly, I want to add my sympathies to anyone who was a victim of sexual or physical abuse by Sir Cyril Smith.
Having reviewed the full history of this case, I am satisfied that numerous attempts were made to expose his activities but for various reasons this did not happen.
That will be of little comfort to the people who were brave enough to recall their traumatic experiences, but will never see justice done in court.
However, I hope that by publicly acknowledging what happened 50 years ago it will give those people some sense of justice.
Police say they are "now publicly acknowledging that young boys were victims of physical and sexual abuse committed by Sir Cyril Smith".
Former Liberal MP Sir Cyril Smith was accused of abusing young boys in Rochdale during the 1960s, by Labour MP Simon Danczuk in the Commons