Hall was responding to an article that appeared in The Times on Saturday (29 July), which raised concerns about freelance journalist Alison Smith-Squire, who allegedly acted as spokeswoman for Charlie Gard's parents while also selling stories about them via her business Featureworld.
Asked whether her work constituted a conflict of interest, Smith-Squire told PRWeek: "The Gard family contacted Featureworld, a long-standing news agency, to help publicise their case and subsequent media interest. As with all interviewees, the arrangements must remain confidential.
"Featureworld puts interviewees first and they prefer having one trusted person deal with all their media."
The CIPR said any person working on behalf of a client should not allow conflicts of interest to arise.
Hall told PRWeek the case highlighted "a series of issues" for PR professionals and their clients, adding that Smith-Squire was not a member of the CIPR.
Hall said: "From a client's perspective, it spotlights the importance of hiring a professional with the appropriate accreditations. The adviser should also be a member of a professional body such as the CIPR or PRCA, which have a code of conduct that must be adhered to."
As a result of The Times' article, the CIPR has reiterated its stance on the ethical responsibility of practitioners and provided guidelines on professional practice to help benefit both PRs and clients.
Eleven-month-old Charlie Gard died on Friday 28 July after suffering from a rare genetic condition.
UPDATE ON THURSDAY 3 AUGUST: Smith-Squire asked PRWeek to clarify that she was not paid to act for Charlie Gard's parents. She also disputed the fact that she was acting as a PR representative.