The MP who uncovered a string of abuse carried out by late Liberal MP Cyril Smith called for "an amnesty" for some social workers and police officers, so they can come forward and give evidence without fear of retribution.
Simon Danczuk told Good Morning Britain he had been approached by those who had investigated some of the alleged historical sex abuse who wanted to come forward, but were unable to because they "were made to sign gagging orders".
"We need to ensure that the inquiry creates some sort of freedom and space for these people to share their knowledge and experience of investigating child sex abuse, or the inquiry won't go anywhere."
The Baroness says she did not consider the "difficulties" caused by her background and family connections to the child sex abuse inquiry.
Questions have been raised of former High Court judge Baroness Butler-Sloss since her appointment last week.
22 police officers are now assigned to Operation Fernbridge - the probe into claims of a Westminster cover-up of sex child abuse.