Nasa has once again been accused of covering up the existence of alien life, after an astronaut captured footage of a UFO.

The mysterious object was spotted entering Earth's atmosphere by one of the crew of the International Space Station.

Despite assurances from the space agency that it is just a meteor, conspiracy theorists remain convinced that it is evidence of extra terrestrials.  

Italian astronaut Paolo Nespoli shot the clip, which shows a fiery ball of light racing towards the Earth's atmosphere.

The ISS crew member believes that the object could be space debris, but both the space agency and alien enthusiasts have rejected this explanation.

Tyler Glockner, who runs alien hunting YouTube Channel SecureTeam10, believes it is more proof of a government conspiracy to hide the existence of aliens. 

Nasa has previously been accused of covering up an alien sighting after a video surfaced showing six UFOs passing the ISS live-stream, seconds before the feed was cut and replaced with images from a camera showing the inside of a briefing room.