I was hunting UFOs, says Pentagon's UK hacker

So do aliens exist? Yes, according to McKinnon.

He said he came across a group called the "Disclosure Project", which had expert testimonies from senior figures who said technology obtained from extra-terrestrials did exist.

He said one NASA scientist reported that the Johnson Space Centre had a facility where UFOs were airbrushed out of high-resolution satellite images. So, he broke in to see for himself.

"I saw what I'm convinced was some kind of satellite or spacecraft but it was manufactured by no means I have ever seen before -- there were no rivets, no seams, it was like one flawless piece of material. And that was above the Earth."