Gwynedd-born presenter Sian Eleri investigates what started with a UFO sighting by 14 schoolboys in a Welsh village, but spiralled into a wave of ‘close encounters’ and claims of the biggest mass sighting in British history.

Following on from the success of the first series, which has been streamed over 2.7 million times on BBC iPlayer, Radio 1’s Sian Eleri is back diving into a new realm in the world of the paranormal – UFOs.

The trailer for brand new documentary series Paranormal: The Village That Saw Aliens has been released.

The series is a co-commission between BBC Three and BBC Wales and follows the successful first series Paranormal: The Girl, The Ghost and the Gravestone.

Radio 1 presenter Sian, from Caernarfon, said: “It was a thrill to fly into a new celestial realm in the paranormal universe. The world of UFOs, extra-terrestrial activity and other theories around what could exist in our skies is vast, intriguing and ominous. It’s been eye-opening to explore such open-ended issues and this series continues to challenge my beliefs - I can’t wait for its launch so viewers can make up their own minds on the case”

The case made headlines around the world when along the south and west coast of Wales over several years the 1970s and 1980s, dozens of ordinary and unconnected people in seaside resorts and rural villages reported a spate of unexplained and terrifying sightings. Reports ranged from a UFO sighting by 14 schoolboys, to a local hotelier claiming she saw a spaceship. A wave of reports of close encounters in the area followed, resulting in claims of Britain’s biggest ever mass sighting.

Sian’s first mission is to track down the schoolboys whose “alien” encounter in the village of Broad Haven, Pembrokeshire triggered it all. With access to the original investigator’s case archive which had been locked away and to those at the heart of the case, Sian sets out to uncover what really happened. She starts out as a sceptic, but in a series of chilling and increasingly bizarre twists and turns, Sian is left questioning everything she thought she knew.

Paranormal: The Village That Saw Aliens is produced by Twenty Twenty Productions Ltd for the BBC. Director of Programmes is Ruth Kelly and the Executive Producer is Jo Hughes. Series Director is Rory Jackson and Series Producer is Hannah Horan.

Paranormal: The Village That Saw Aliens is available on BBC iPlayer.