Michael Sheen joins new series of BBC Radio 4’s award-winning podcast Buried

Buried: The Last Witness is the untold account of one of the world’s first-ever whistleblowers on ‘forever chemicals’. When the podcast hosts uncover a box of unseen evidence and affidavits from a dead witness, it sparks a journey into one of the UK's darkest environmental secrets. In a surprise twist, they discover that the actor Michael Sheen recorded the witness's final testimony.

Following their disturbing investigation into a toxic dump at Mobuoy Road in Northern Ireland, investigative journalists Dan Ashby and Lucy Taylor return with an explosive new story for BBC Radio 4’s award-winning environmental documentary podcast Buried, on 24 June.

Across 10 episodes, the intrepid trio follow the trail to some of the most toxic sites in the country – and the world – to uncover the horrifying legacy that PCB chemicals are having on the environment, our communities and even our food chain.

The witness's recorded testimony says he was dying from the chemicals and more people would follow. Were they right?

Buried: The Last Witness will reveal the results of a one-year investigation involving dossiers of evidence, unseen documents and exclusive testing of British soil, supermarket food and even human blood.

Dan Ashby says: "Most true-crime series have a victim, who we all feel empathy for. But in this one, we know the poison, we know the culprits, but the scary question is this: are we all the victims? I've never recorded an investigation that is at once so universal, and so deeply personal."

Lucy Taylor says: "Every day, sometimes every hour, we have obsessed over the life of one man. He was brilliant, polymathic and eccentric. He is the most unlikely environmental hero. But who really was he, and what did he see? Could that one field, in 1967, change all of our lives? Once you see what he saw, Buried: The Last Witness becomes necessary listening."

Michael Sheen says: "It's hard to get your head around. This story is about the first of the forever chemicals. And there are so many of them since then. We want people to understand what they are doing right now. There were moments in this story when a little voice inside my head was screaming."

Buried: The Last Witness is available as a box set on BBC Sounds and broadcast weekly on BBC Radio 4 from 24 June.