Home Affairs committee chairman Keith Vaz said that any inquiry into historic allegations of a child sex abuse ring at Westminster must be independent of Parliament.
Mr Vaz told BBC Radio 4's World At One:
I don't think Parliament should be conducting inquiries. This is not the role of the Home Affairs Select Committee.
We came to a stage on phone hacking where we thought the evidence was so huge and the neglect so great that it really had to go outside Parliament. We have reached that stage at the moment, not because people can't be trusted to conduct the inquiry, but (because) we don't have the expertise and the ability to do it.
This must go outside Whitehall, it must go outside Westminster to independent figures, who can examine what Simon Danczuk, Tom Watson and others have said.
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.