So, what's the story?
I first came across Andrew Hunter aka Prince Andre de Guise last year, when a correspondent on a newsgroup site posted a question about him, asking whether his titles were bona fide. It seemed clear to me immediately that they were not: for instance, they do not appear in any known reference work; they allegedly pass through the female line, and to their husbands, and despite illegitimacy. On a hunch, I had a quick look at the Winchester College Old Boys' registers, and was able to see how the claims had been advanced and augmented over the years (NB the entries are autobiographical):

Furthermore, the London Gazette contains a record of the Deed Poll by which Andrew Hunter adopted the surname 'de Guise Roussel' in 1958 - no mention of princely titles here:

Surprisingly, de Guise's remarkable claims to possess no fewer than three princely titles, and the fabricated pedigree, were defended voluntarily and vigorously on-line in September 2005 by Frederick Hogarth, the editor of Baronage Press - an experienced and respected researcher in the fields of genealogy, heraldry and nobility who has built up a reputation for exposing frauds. Considerable discussion ensued.
It transpired that de Guise was formerly an associate of the late Harold Brooks-Baker, and has been involved in the sale of purported French titles for some years. He seems to live in a chateau near Nancy, from which his 'White Greyhound' organisation is run.
You can see him and his claims at this website:
http://www.levrierblanc.org/web/profiles.asp
Or take a look at his recently expanded www.gothainternational.eu site, if you are in the mood for a laugh. He tells us, inter alia, that his titles "are not used, except for charitable purposes". How ever do you suppose they slipped into his Winchester College Old Boys' entries?
Here are a couple of his baubles:

So much for being told that the "Order" is merely an umbrella for charitable purposes without the accoutrements of chivalry. Here is a photograph of de Guise at a recent "special ceremony to officially and publicly promote" one of the members from the Grade of Companion to the next rung up, that of 'Dame':

In considering his long-standing business of title sales, you might like to look at an expert's explanation* of why it is considered impossible to sell French noble titles in the way that de Guise purports to do:
http://www.heraldica.org/topics/france/titlesale.htm
Despite all this evidence being available, de Guise continues to advance his claims, and Baronage Press - the self-styled scourge of fakes - has not withdrawn their endorsement or support; indeed, astonishingly, they have admitted to acting as a broker in his purported titles sales.
Perhaps the final word for now should go to His Imperial & Royal Highness The Archduke Otto, last Crown Prince of the Austro-Hungarian empire and Head - since 1922 - of the House of Lorraine to which the erstwhile Andrew Hunter claims to belong (and whose arms he has usurped):
"20 September 2006
Dear Mr Andrews-Reading
Thank you for your letter about the prince of „Guise-Lothringen“.
A person with this name is completely unknown here..."
As they used to tell me in Law School: Caveat Emptor!
* Thanks to Francois Velde for allowing me to link to his learned site; the appearance of the link here does not indicate that he is associated with or in any way endorses my site. MA-R