THE mystery surrounding Rudyard Kipling's son has finally been solved - more than 100 years after his death.

Soldier John Kipling went missing during the Battle of Loos in the First World War in September 1915.

His father, Britain's most popular writer at the time, was left devastated and spent four years trying to track down his lost son.

The Nobel Prize winner for Literature desperately hoped he had been taken prisoner or even gone mad and been locked up.

But with no news, he fell into a deep depression at his country retreat Bateman's near Burwash.

The tragedy changed his writing forever. Gone were the adventures of the like of the Jungle Book, instead replaced with sombre war poetry.

After the war he worked with Winston Churchill to ensure all soldiers' gravestones were the same shape and size, regardless of military rank. Kipling also coined the phrase "known unto God" which features on the headstone of all graves of unknown soldiers.

Writing for the Western Front Association, researcher Joanna Legg, believes she has final solved the mystery of what happened to John Kipling.

On September 27, with the battle at its fiercest, John's battalion was ordered to cross open ground and head towards Chalk Pit Wood.

They are said to have dug in opposite the Germans and faced machine gun fire. Sometime in the next hour he disappeared.

Ms Legg said the story then becomes confused with differing eyewitness accounts.

Some suggest he went forward towards the enemy. Others said he headed left towards a farm. His colonel later wrote he had been spotted near the enemy, hobbling and with a head injury.

For nearly 80 years - his father died in 1936 - his fate remained a mystery until in 1992, the Commonwealth War Graves Commission changed the inscription on a gravestone of an unknown soldier to read John Kipling.

This prompted huge debate - but now Ms Legg thinks she has got to the bottom of it.

She said: "There were three issues. Firstly, the grid references seemed to suggest that this body had been found three miles away from where John had been fighting. We have now shown that this was simply a clerical mistake."

The second issue was that another lieutenant had gone missing. She said: "We now know that the second officer had been taken away to a hospital during the battle. He was buried some distance from the battle scene."

The final mystery concerned his rank. The recovered body wore the stars of a first lieutenant but Kipling was officially a second lieutenant. Ms Legg believes this was due to a blip in communication as he had in fact been promoted in June.

One of Kipling's most famous poems, My Boy Jack, is said to be about the heartbreak of losing his son.