thanks for those answers & just to expand the issue a tad: the occurance of this is very recent and quite deliberate. Indeed one of the culprits claims considerable experience at research and wot-not and is I suspect a vested member of a well established society - not this one or any connected with it - the other individual appears to have 'bought' the scam and thus is actively involved.
A simple cease and desist order will not suffice, I'm guessing - so any thoughts on possible remedies will be thoughtfully contemplated...
rodc
Like others, I'm struggling to work out exactly what the problem is, though it may be that rodc's answers to earlier questions may help with this.
My understanding so far is that by his/her own account, rodc has very little information about the person who has been "foisted" on to another tree, but is concerned about someone who claims to know more than rodc does.
Surely one of the first things to do is to query the source of the information. If the researcher can substantiate the connection he/she has made, then it may well break down one of rodc's brickwalls. If they can't, then the course of action may depend on what they intend to do with the information. If it's just a vanity project, like so many online trees, you may have to let it go, but if it's in order to claim an inheritance or similar, there might be a cause for greater concern. The best you can say, though, is that the connection they claim is "supposed" or "unproven"; with your own lack of information, can you actually disprove it?
The possible link to a society may be worth bearing in mind: if it can be demonstrated that the researcher has falsified his/her results, then any society in whose name he claims to act may be interested to hear about it; or, if appropriate, a relevant professional body such as AGRA - The Association of Genealogists and Researchers in Archives. However, as above, it may come down to what can and can't be proved.
Might it actually turn out to be the case that the researcher produced something appropriately cautious, with the alleged connection as one of a range of possibilities, which the other person (only) has then seized upon and treated as absolute truth? Again, this would point to the necessity of finding out exactly what the researcher said, and why.
Arthur