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Documents revealing new UFO sightings have been made public on the FBI's official database.

The previously classified records, which contain information of extraterrestrial encounters dating back 60 years, show eye-witness accounts of flying saucers and aliens.

Nick Pope used to be a government UFO investigator. He tells BBC Radio 5 live's Tony Livesey about lights in the sky and conspiracy theories.

For more Radio 5 live interviews, please visit the best bits page.