But an online trail followed by the Daily Mail leads inexorably to a 43-year-old former civil servant called Geraldine Curtis.
From her run-down home in South London, Miss Curtis has repeatedly attacked and denigrated the Welsh classical singer on a personal blog.
She has now been blocked from the star’s personal Twitter page.
Target: Miss Jenkins objected to 'hurtful and damaging comments'
But she broke her silence on Sunday after appearing on the BBC’s Something For The Weekend show, where presenters asked her questions supplied by the public. To viewers, the question: ‘What is the difference between a mezzo soprano and a bel canto?’ appeared inoffensive enough.
However for Miss Jenkins the identity of its supplier - named as ‘KJMezzo’ - was the last straw.
Within half an hour, she issued a withering statement describing her anonymous attacker as ‘sad’ and a ‘bully’. Shortly afterwards KJMezzo’s Twitter account was shut down, apparently in response to a request by the singer, and a blog written in the same name also disappeared.
Star struck: Geraldine Curtis with German tenor Jonas Kauffman
Moments later, another contributor asked: ‘Is it you, Geraldine Curtis?’
Interviewed by the Mail at her semi-detached cottage in Brixton, Miss Curtis insisted she is not the person behind the KJMezzo Twitter account and did not send in the question to the BBC show on Sunday which so enraged the Welsh star.
‘I did not watch it - I did not know it was on,’ she said. ‘I had a stinking hangover. Too much red wine on Saturday.’
She later admitted, however, that she had watched the show online on the BBC iPlayer.
Miss Curtis's Facebook photo album headed: Stalking
‘She can’t sing,’ said Miss Curtis. ‘She is not an opera singer. She criticises opera singers. For years her website has said that opera singers are histrionic, overweight and frumpy.
‘She claims that she has “brought opera to ordinary people” who are too stupid to like opera, that’s her attitude.
‘She is very critical of other people but she cannot take criticism. My comments about Katherine Jenkins are critical but she is in the public eye.’
In recent days, Miss Curtis has clashed on her Twitter account with Samantha Cox, a representative of Miss Jenkins’s management company.
Claiming that if you criticise Miss Jenkins ‘her heavy mob turns nasty’, Miss Curtis tweeted: ‘If my Twitter account suddenly disappears, blame Katherine Jenkins … and check my blog for details!’
Earlier Miss Cox had tweeted to Miss Curtis: ‘The vile things that come out of your mouth! ... calling someone else horrible and nasty is like the pot calling the kettle black!’
One more from the Facebook file: Miss Curtis with Erwin Schrott
Examples include an entry in which she says: ‘Dress is too tight … she’s a Barbie doll … she looks cheap/needs her roots doing.’
She claims Miss Jenkins exploits her appearance at the Remembrance Sunday service and the death of her father when she was 15 to sell records, adding: ‘She says, “Feel sorry for me my daddy died. Buy my album”.’
And she accuses Miss Jenkins of ‘jumping on the bandwagon of the abuse of female bloggers’ with her own claims that she is being bullied.
On her personal Twitter page less than 24 hours after Miss Jenkins’s outburst, Miss Curtis wrote: ‘I expect KJ & her entourage will now accuse me of cyberbullying. They’re on a roll, with traction. Criticism is not bullying.’
On her Facebook page, Miss Curtis has posted an album of 46 photographs showing her with opera stars including Placido Domingo, Erwin Schrott, Jonas Kauffman and Rolando Villazon. Its title is ‘Stalking’.
A spokesman for Miss Jenkins said she was glad the online hate campaign against her appeared to be over and added: ‘Katherine is pleased that the Twitter account that was sending the abusive messages has now been deleted.
‘She loves using Twitter and it’s great that she can continue using it without the constant hurtful and damaging comments made by that individual.’