Charles Dickens made her take a virginity test to silence the gossips and safeguard his reputation as a guardian of Victorian family values.

But could a diamond ring for sale at auction be final proof that the Britain's most famous novelist did indeed have a longstanding affair with his sister-in-law Georgina Hogarth?

The owners say the ring was passed down to them from a secret love-child born to Dickens and his wife's sister who lived with family.

The claims will be bombshell to fans already reeling from revelations that, despite his very public protestations to the contrary, the great moralist did not always live a life of faithful domestic bliss with his wife Catherine and their 10 children.

Revered for his moral tales

Most historians have come to believe in recent years that in his late 40s the most famous literary figure in England fell for an 18-year-old actress and abandoned his wife to embark on a 13-year love affair.

But the famous virginity test has always been used to put paid to persistent rumours that the man revered for his moral tales was sleeping with his wife's younger sister.

Now, nearly 150 years after his death, Nigel Ward auctioneers of Pontrilas, Herefordshire is selling the ring, inscribed "Alfred Tennyson to Charles Dickens 1854", and which the owners say was passed down from illegitimate child, Hector Charles Dickens.

Mr Ward said: "Analysis of the documentation leads one to believe that Hector Charles Bulwer Lytton Dickens, frequently known as Charles Dickens (the Younger) was the son of the renowned Charles Dickens and Georgina Hogarth, who was his sister-in-law and was employed as their housekeeper.

"This has also long been the understanding of the ring's custodians. "

Dickens reportedly arranged for Georgina to undergo a humiliating virginity test to silence whispers.

But in his will Dickens praised trustee Georgina as his most trusted friend and left her most of his jewellery and £8,000 cash, far more than his estranged wife and his mistress.

The owners of the ring, who do not wish to be identified, also have a press cutting from The Statesman of December 31, 1922, that appears to support the claim.

The newspaper has a picture of a Mr Hector Charles Dickens, youngest son of the author Charles Dickens, born in 1854, in Calcutta where one of the writer's legitimate sons died.

The photograph purports to show Hector Dickens at his brother's grave and says: "Mr Dickens, who has an hotel in Simla, the Goodwood, has worn for many years a gold ring presented by Alfred Tennyson to Charles Dickens".

In 1858 Dickens left his wife but issued a statement denying "monstrous misrepresentations" about his personal life on the front page of his journal Household Words and claimed the cruel rumours doing the rounds were damaging innocent people dear to his heart. Before his death at the age of 58 in 1870, Dickens burned most of his letters in what many now regard as a cover up that continues to this day.

His daughter Katey was branded mad after claiming Dickens had a secret love-child with his actress lover.

Now the diamond ring in could prove the self-confessed skeleton in the cupboard of this great writer could well have been a love-child with his sister-in-law.

If the auctioneers can prove the 0.9 carat ring has such an interesting past it could turn out to be a historical gem worth far more than the £25,000 to £35,000 guide price.

Mr Ward said: "I have spoken to some Dickens people over the phone and they are sceptical about it, but they were always going to be.

"People are always sceptical about something new they know nothing about.

"But many believe Dickens had several illegitimate children during his lifetime and there is quite a lot to infer the owners are the descendents of a son he did not recognise.

"The people selling the ring are convinced and if it can be proved beyond all doubt, it will make a dramatic difference to the value."