The BBC Director General Tony Hall has said he will not reveal how the BBC learned about a police warrant to search Sir Cliff Richard's home in advance.
In his letter to Home Affairs Select Committee chairman Keith Vaz, he said the anonymity of sources was "a key principle for all journalism" and "for that reason the BBC will not be providing details about the source".
He added that the BBC was an independent organisation and that he would not "elaborate on detail of our editorial processes".
More top news
Autumn weather arrives for the early part of the weekend. Brighter and drier later.
The bombs, which are designed to penetrate military bunkers, completely destroy buildings and leave people buried under tons of rubble.
Loretta Lynch says she believes that the world has the resources to deal with the Syrian conflict and resulting issues.