LOUIS THEROUX – SAVILE, BBC2, 9pm

LOUIS is still puzzling about Savile. His original documentary about the DJ was motivated by thinking he had a secret, but no great revelations were made. Now he returns to the topic, armed with hindsight, to meet Savile’s victims and colleagues and ask how Savile was able to trick him, and so many others.

There are some very honest and graphic descriptions of Savile’s abuse here.

One woman remembers his abuse causing her to retch. Worried for his Rolls-Royce’s upholstery, “he flung the car door open and said not in the car!”

But others, such as a former BBC producer, and Janet, his PA of 20 years who was given away at her wedding by “Jim”, still can’t accept he was an abuser.

The victims tell Louis he was “hoodwinked”, “gullible” and “silly” to have been taken in by Savile.

In his defence, Louis says he felt he was “borderline creepy but at the time, like others, I felt this was part of his comic persona.”

He also asks how Savile managed to charm and overwhelm people. “To understand his crimes we should all remember how we were beguiled.”

THE HUNT FOR THE NAZI GOLD TRAIN, BBC2, 8pm

WE always hear that TV is obsessed with the Nazis but, to this show’s credit, it takes a different tack from the others.

Dan Snow tells the story of the Nazi gold train, something which sounds like a fairy tale.

In 2015, two amateur researchers claimed to have found the site of the infamous Nazi gold train. It was rumoured to have been loaded with treasure at the end of the war as the Nazis fell into retreat.

This treasure train was supposedly then hidden in a tunnel deep in the southern Polish forests and, apparently, lost.

So when two local treasure hunters claimed to have found the site, the world was amazed.

Snow joins the hunters as they begin their excavation of the site.

He also tells us about Riese, an underground cavern built to permit armament production safely away from enemy fire.

With Riese supposedly linked to a nearby castle via secret tunnels, was this planned as a last hide-out for Hitler?