F-15 fighter pilots were unable to intercept a mystery UFO which was seen on radar flying at incredible speeds before vanishing. The unexplained incident happened on the evening of October 25 over the Pacific northwest in northern California.

The white object was first spotted on radar before there were a series of eyewitness accounts from commercial pilots flying north over Oregon.

Express.co.uk reported on the incident at the time, after it apparently became invisible to radar and US Air Force (USAF) F-15 fighter jets were unsuccessfully scrambled to intercept it.

Now, video and audio recordings of the radar operators, who remain baffled by what they saw, after been released under the Freedom of Information Act.

They were obtained by Thedrive.com which said: "We present what could be one of the most insightful instances of official documentation surrounding such an encounter that had already been confirmed to have occurred by both the Federal Aviation Administration (FAA) and the USAF.

"These materials include fascinating audio recordings of radio transmissions and phone calls made as the incident was unfolding, as well as pilot interviews, and conversations between FAA officials made in the aftermath of the highly peculiar incident."

To read more and view the video, click here.