The committee may only rule on registration in the presence of the chairman and at least five of its members. Where one of the members or the chairman of the committee has authority over the applicant or is related to him or her by blood or marriage up to and including the fourth degree, he or she shall abstain from sitting. No refusal of registration may be made by the committee without the interested party having been heard or called at least fifteen days in advance by registered letter with acknowledgement of receipt.
.