In 2014, PR guru Max Clifford wandered up behind Sky News reporter Tom Parmenter and mirrored his hand gestures as he spoke straight to camera. Parmenter responded with a grin and a matey 'you ok, Max?' Out of context, it would just seem like a moment of levity between two individuals in different corners of the media, one trying to do their job, the other killing time before heading off to his next assignment.

When you realise the full context, this deadpan frivolity takes on an air of menace and reprehension. Here is Max Clifford interrupting a news report about his own trial at Southwark Crown Court where is he accused (and will soon be found guilty) of terrible sex crimes across three decades against under-age girls. Is this the action of man who is relaxed about his own ability to wriggle free from justice or is it a final symbolic act of someone who controlled the media for years, bending everyone including newspaper editors and chat-show hosts to his malevolent will? You may well choke on your own disbelief at the clip of Terry Wogan chirpily introducing Clifford as 'the keeper of the flame of truth'.

One key witness in this documentary is the dead convict's biographer Angela Levin, who was shocked with Clifford's openness in detailing his sexual proclivities (from creepy voyeurism to manipulative pimpdom) while three of the survivors put his actions as well as his despicable hypocrisy on trial. Particularly telling is the footage of Clifford flying the flag for Operation Yewtree and insisting that he would help nail all those nasty celebrity sex criminals when, all along, he had more in common with the likes of Jimmy Savile and Gary Glitter than any of us knew.

Max Clifford: The Fall Of A Tabloid King is excellent in putting this damning footage together and in sealing interviews with those he abused as well as the media personnel who, it seems, were totally disarmed by his smooth-talking ways. But none of it offers any real clues as to why his seediness warped into sadism. The best we get is an admission from his own mouth that he was a born liar who would get what he wanted in the service of those desperate to tell their story, no matter how sordid. But even that is a falsehood when it becomes clear that his number one client was always Max Clifford.

Channel 4, Monday 1 March, 9pm.