What is the test for disqualification of a person for having a personal interest in a curling facility?

The principle involved in these proceedings is expressed clearly and with few words by Field J. in Regina v. Mayor and Justices of Deal; Ex parte Curling (1881), 45 L.T.N.S. 439 at 440, and I quote: "With regard to a pecuniary interest, however remote, however slight, the authorities are clear that, when it exists, the person possessing it is necessarily disqualified."

Vaughan Williams L.J. in Rex v. Sunderland Justices, [1901] 2 K.B. 357 at 371, enunciated the principle with this statement: "If he has personally a pecuniary interest or an interest capable of being measured pecuniarily, the law raises a conclusive presumption of bias. For reasons of policy, which hardly require explanation, it is not thought convenient, where there is such an interest, to go into the question whether he in fact acted partially or impartially. A bias is presumed from the mere fact of the existence of the interest."