In October 2015 President Xi Jinping was welcomed to Britain on a state visit, the event was seen as the pinnacle of the so called 'Golden Era' of warm relations between the UK and China. Over a decade later, and despite a cooling of that relationship, File on 4 Investigates discovers Chinese state money and influence reaching far into UK companies and universities as China targets British chip and blockchain technology, and asks whether enough is being done to mitigate the threat to national security.
Presenter: Paul Kenyon Producer: Anna Meisel Research: BBC Verify Junior Production Manager: Tom Dunster Production Management Assistant: Tim Fernley Technical Producer: Cameron Ward Editor: Tara McDermott