The ancestral home to the Earl of Lichfield has once again whetted the appetite of Holy Grail scholars by unveiling an enigmatic artefact.

A small newspaper cross, found tucked into the roof of the mansion at Shugborough Hall in the early 1990s, has never been on display.

But its shape – that of a Cross of Lorraine, as used by the Knights Templar – can only fuel further speculation as to the stately home's hidden connections.

"We have no idea why the paper cross was deposited in the mansion house's roof space," said Shugborough spokeswoman Corinne Caddy.

"However, there are many theories regarding the Anson family's connections with secret societies and, more particularly, surrounding the code on the Shugborough Shepherd's Monument – which some say leads to the Holy Grail."

The estate attracted worldwide publicity four years ago when Bletchley Park's codebreakers attempted to crack the indecipherable code on the garden monument.

Now the paper cross, recovered from the depths of Shugborough's archives after almost two decades, could re-ignite the quest to uncover the truth.

Currently on display as May's 'object of the month', it appears to have been deliberately torn from newspaper into the shape of a Cross of Lorraine.

And the newspaper in question is the British Chronicle of May 20, 1794.

"Perhaps it was simply placed there as a good luck symbol," added Mrs Caddy.

"Perhaps it is purely accidental that a piece of newspaper should be ripped into a shape resembling the Cross of Lorraine.

"Or, perhaps, it is another clue in the mystery regarding the secret of the Shepherd's Monument."

In any case, there is already enough speculation around Shugborough to doubtless intrigue the fictitious symbologist Robert Langdon, hero of Dan Brown's blockbuster The Da Vinci Code.

The Cross of Lorraine was used as a symbol by the Knights Templar after the Patriarchs of Jerusalem granted its use to them during the Crusades.

Its image has been found scratched into the walls of cells where some Knights Templar were held before execution.

Joan of Arc also adopted the Cross of Lorraine as her standard.

In the 15th century, Rene d'Anjou – who later became the Duc of Lorraine – kept a piece of wood in the shape of the Cross of Lorraine believing it was part of the True Cross of Christ.

Later in the 18th century, Shugborough's Anson family supported the then Duc of Lorraine in the Austrian War of Succession. He went on to become the Holy Roman Emperor.

Some people believe members of the House of Hapsburg-Lorraine are descendants of Jesus Christ.

The cross will remain on display in the mansion house until the end of the month, when it will be replaced by another interesting object from Shugborough's stores.

(Original headline: Cross riddle at Shugborough leads to new Grail quest )