Haven't seen the BBC doc, but there has been a FANTASTIC Italian-made mini-series showing here called 'il capo dei capi', shown here as 'Corleone'with english subtitles. It's available on you-tube in it's original Italian, or with French subtitles^^, but i'm sure a quick google should get a result. I can't tell you how good this series is, the best i've ever seen, the acting and characters are absolutely nailed-on.