Deepfake AI has the potential to undermine national security, a cybersecurity expert has warned.

Dr Tim Stevens, director of the Cyber Security Research Group at King's College London, said deepfake AI - which can create hyper-realistic images and videos of people - had potential to undermine democratic institutions and national security.

Dr Stevens said the widespread availability of these tools could be exploited by states like Russia to 'troll' target populations in a bid to achieve foreign policy objectives and 'undermine' the national security of countries.

He added: 'The potential is there for AIs and deepfakes to affect national security.

'Not at the high level of defence and interstate warfare but in the general undermining of trust in democratic institutions and the media. 

'They could be exploited by autocracies like Russia to decrease the level of trust in those institutions and organisations.'

Here, MailOnline has put together a deepfake test as well as everything you need to know about deepfakes. What are they? How do they work? What risks do they pose? Can you tell the difference between the real thing and AI?

If you've seen Tom Cruise playing guitar on TikTok, Barack Obama calling Donald Trump a 'total and complete dipshit', or Mark Zuckerberg bragging about having control of 'billion's of people's stolen data', you have probably seen a deepfake before.