The official record showing the mysterious disappearance of three lighthouse keepers more than 100 years ago is available to see online for the first time.

An extract from the Lightkeepers’ Register from 1900 shows an entry stating “disappeared on or about 15 December 1900” regarding the three men who went missing during a storm at Eilean Mor in the Western Isles, or Outer Hebrides.

The three keepers of the Flannan Isles, which lie about 21 miles off the coast of Lewis, were: James Ducat, 43, Donald MacArthur, 40, and Thomas Marshall, 28, They disappeared on December 15 1900.

Relief was sent after news had reached the Northern Lighthouse Board but by the time it arrived on December 26, it was too late.

An investigation concluded the men had drowned having been swept out to sea in the storm but their bodies were never found.

The mystery surrounding the men continues more than a century on and theories as to what may have happened include murder, abduction by foreign spies or a more supernatural explanation.

Their disappearance has been interpreted many ways over the years, with the tale being a focus of the 2018 film The Vanishing, starring Gerard Butler.

Now, the document from the time has been released by the National Records of Scotland (NRS), via the genealogy website, ScotlandsPeople.

The last lighthouse was automated in 1998 and these records shine a light on the working lives of over 1,300 men in a profession that has now mostly passed into history

More than 2,000 new scans of records from the Northern Lighthouse Board give details of more than 1,300 lightkeepers, working in 92 lighthouses between 1837 and 1921 all across Scotland.

They also include Bell Rock, the world’s oldest working sea-washed lighthouse.

Keepers worked long days and nights maintaining light and fog signals, as well as cleaning and ensuring the upkeep of isolated stations in harsh conditions.

They could be isolated from family and friends for long periods, living in cramped spaces often with only basic hygiene facilities.

Jocelyn Grant, NRS outreach and learning archivist, said: “The last lighthouse was automated in 1998 and these records shine a light on the working lives of over 1,300 men in a profession that has now mostly passed into history.

“The Northern Lighthouse Board records are frequently requested by visitors to our buildings. If your ancestor worked in a Scottish lighthouse, there’s a good chance you will find them here.”