The adviser, known to FTAdviser, had posted several memes on their personal facebook site, which had been passed onto FTAdviser and the CII.
As reported by FTAdviser earlier this year, the images included one of Meghan Markle and Prince Harry as golliwogs, as well as a joke about the Holocaust.
The adviser had stressed that these images had not been created by them, but shared among a private group of friends, without any intention to offend.
The mere causing of offence will not, of itself, justify intervention by the CII.CII communication
Moreover, the adviser believes the images had been stored and disseminated by someone who was seeking to undermine both the adviser and the company for which they work.
The adviser said: "It probably shows how easily a vindictive attack caused me grief while clearing my name."
This point was made to the CII in the course of its investigation but, according to an email seen by FTAdviser, the CII has closed the case.
The communication said: "Having considered your responses we have decided to close this case."
It did provide guidance to the individual, as a member of the CII, in relation to comments on social media.
The communication said: "The Courts have found that a regulatory or professional body may, in pursuit of legitimate aims (such as safeguarding the public and upholding confidence in the relevant profession), interfere with the right to freedom of expression of its members or registrants."
It added: "Put simply, where a member of the CII makes comments on social media which fall short of professional standards and/or could undermine public confidence in the profession, the CII may bring disciplinary proceedings against the member, provided this is necessary and proportionate."
While it is not easy to draw the line, the CII added: "The mere causing of offence will not, of itself, justify intervention by the CII, but where derogatory, insulting, intimidating or abusive language is used, intervention may be justified."
It said the display of the Facebook posts in question had been "below the standards" of conduct expected of the adviser by the CII.
However, it added: "On this occasion, taking into account your explanation for your posts on your personal Facebook account, and recognising that we have not previously provided you with guidance in this area, we have decided to close this case."