I've never listened to (or indeed heard of) this before)but it came up as a suggestion today and I started with Series 5 episode 1. It's worth listening to from about 9.50 ish, with references to Kathleen Stock and the Nolan Investigates.
www.bbc.co.uk/sounds/play/m001154r
The format isn't one I've noticed before - it's just soundbites with no commentary, and it's surprisingly effective. I'm going to go back and listen to other episodes.