A video showcasing three lights moving in the sky has led to many speculating whether a spy "TR-3B" type UFO flew over Russia last week.

YouTube channel UFO Today posted the video and wrote: “The object is moving at a very slow pace, too slow to be classic airplane.

“The speed at which this object was moving is physically impossible for any airplane build by mankind.

“At a certain point in time the aircraft loses propulsion in one of the three engines, but that does not stop it.

“It continues its way through earth's skies.

“Reports generally describe this class of UFOs as large, silent, black triangular objects hovering or slowly cruising at low altitudes over cities and highways.

“Sightings usually take place at night. These objects are often described as having pulsing coloured lights that appear at each corner of the triangle.”

TR-3B is alleged by conspiracy theorists to be a secret "black project" spy craft of the US Government that can be flown into space.

The title of the video claims that it is the “best evidence ever” that UFO’s exist.

Despite the claims made by the YouTube channel, others have attempted to debunk the video.

Nigel Watson, the author of the UFO Investigator's Manual, a book examining UFO sightings, stated that judging the vehicles speed could be harder than the theorist predicted.

He said: “At night it is hard to gauge the distance and size of an object or lights, which in turn makes it difficult to judge their speed.

“As this seems to be flying slower than an aircraft I'd say it is a drone with lights on it.

“Drones can hover and move slowly, with little noise.

“So I don't regard this video as evidence for ETs visiting us.”