91.—In any disciplinary hearing under section 90 or in any proceedings, a certificate, issued under section 89(5), purporting to be signed by a person employed or engaged in the analysis of samples provided under section 89(1) at an analysis body, stating the capacity in which the person is so employed or engaged and stating any one or more of the following, namely—

(a) that the person received the sample sent under section 89(5) to the analysis body,

(b) that, for such period as is specified in the certificate, the person had in his or her custody the sample so sent,

(c) that the person gave to such other person as is specified in the certificate the sample so sent,

(d) that the person carried out the analysis of the sample, and

(e) the results of the analysis,

shall, unless the contrary is shown be evidence of the matters stated in the certificate.