Exclusive: An email sent by a reporter on Newsnight's axed Jimmy Savile investigation suggests editor Peter Rippon played down the story because "it was 40 years ago... the girls were not too young".

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Channel 4 News has seen an email from Newsnight reporter Liz MacKean that details her interpretation of the frustration felt internally as their investigation into Jimmy Savile was pulled. She recalls the reasons Newsnight Editor Peter Rippon gave at the time for shelving the report, a decision she says created "quite a perfect storm".

In the email sent in December 2011, MacKean references the planned Christmas tribute specials, and talks about editor Peter Rippon who has now stepped aside. Rippon's explanation of his decision to pull the report has already been corrected by the BBC. Today, Director General George Entwistle told the culture, media and sport committee that there was no managerial pressure, and the decision was Peter Rippon's alone.

She accuses Rippon of backtracking after commissioning the story: "Having commissioned the story, Peter Rippon keeps saying he's lukewarm about it and is trying to kill it by making impossible editorial demands."

And she details his increasingly desperate excuses to the team who had worked on the story: "When we rebut his points, he resorts to saying: well, it was 40 years ago... the girls were teenagers, not too young... they weren't the worst kind of sexual offences etc"

She writes that she believes: "He hasn't warned BBC1 about the story, so they're beavering away on the special, oblivious."

In response to the publication of this email, the BBC issued a statement to Channel 4 News.

It read: "The BBC has confirmed it has launched an independent review lead by former head of Sky News Nick Pollard which will cover these questions. It would not be appropriate to comment further until these have been concluded."

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