The Earth is wide open to alien attack, a former Government advisor has warned. Nick Pope said the department that formally investigated UFO sightings had closed down, meaning unexplained phenomena were not being investigated. Mr Pope, who ran the Ministry of Defence UFO project from 1991 to 1994, said there had been a series of "highly credible" alien sightings and landings in the UK.
"The consequences of getting this one wrong could be huge," he said.
"If you reported a UFO sighting now, I am absolutely sure that you would just get back a standard letter telling you not to worry.
"Frankly, we are wide open - if something does not behave like a conventional aircraft now, it will be ignored.
"The X-Files have been closed down."
Mr Pope said those working for the MoD UFO project spend their time releasing formerly classified documents in answer to Freedom of Information requests from the media or members of the public.
The UFO expert resigned from his MoD post at the Directorate of Defence Security this week.
He said there was no evidence of UFO hostile intent - but it could not be ruled out.
"There has got to be the potential for that and one is left with the uneasy feeling that if it turned out to be so, there is very little we could do about it," he said.
"If you believe these things are extra terrestrial craft then you cannot rule out that what is happening is some kind of covert reconnaissance."
The MoD insisted that all UFO sightings were investigated for "evidence to suggest that UK airspace has been compromised by hostile or unauthorised air activity.
"Unless there is such evidence, the MoD doesn't attempt to positively identify what was seen."