EXCLUSIVE: Sister, the UK production house run by Jane Featherstone whose recent credits include HBO and Sky’s Emmy-winning Chernobyl and BBC/Netflix series Giri/Haji, has won rights to Helena Merriman’s buzzy podcast Tunnel 29 in what I understand was a highly competitive situation.

Since launching in November on BBC Radio 4, Tunnel 29 has scored more than 5 million downloads. The series chronicles the remarkable true story of a group of students who dug a tunnel from West to East Germany, underneath the Berlin wall, to help people escape the communist regime.

Hodder & Stoughton pre-empted rights to a book based on the series that creator Merriman is writing, and screen rights to that are also part of the package acquired by Sister. The producer confirmed the deal but added that at this stage it was too early to say if it would become a TV or film project.

I understand that there were some heavyweight bids on the table for the property, including from See-Saw (which I hear prepped a package with The Crown director Benjamin Caron), Temple Hill, and Endeavor, among other high-profile outfits on a 20-strong list.

Rights to Tunnel 29 were held by the BBC. Luke Speed of Curtis Brown Group brokered the deal with Sister.