In a secret location in a European city is an archive that contains over a million documents. It’s run by a tough-talking Canadian, Bill Wiley, who set up an evidence-gathering organisation funded by Western governments.

Using undercover criminal investigators operating inside a war zone, the Commission for International Justice and Accountability (CIJA) has spent the last eight years extracting official documents from Syria. Wiley says that evidence will prove that the Assad regime has been responsible for a campaign of torture and murder against its own people.

CIJA's documents are being used right now in a criminal case in the West to prosecute members of the Syrian regime. But there are those who would discredit the evidence and the people who gather it. These include a group of respected academics here in the UK who are accused of spreading misinformation and conspiracy theories about the war, twisting the narrative so that the Syrian regime becomes the victim and the British government bears responsibility for war crimes.

It is a new kind of warfare being fought not on the ground but on the internet. Who will win?

Writer, producer and presenter Chloe Hadjimatheou Editor Emma Rippon Researchers Orla O’Brien and Lara Al Gibaly Executive producer Maggie Latham Sound design and mix Neil Churchill Mark Fleischman played the role of Prof Paul McKeigue and the role of Ivan Commissioner for Radio 4 Richard Knight

Correction: We stated that Feras Fayyad won an Oscar - instead his films were nominated on two occasions for an Oscar but did not win.