5beta-Cholestane-3alpha,7alpha-Diol 12alpha-Hydroxylase Activity

GO:0033779

Catalysis of the reaction: 5beta-cholestane-3alpha,7alpha-diol + H(+) + NADPH + O(2) = 5beta-cholestane-3alpha,7alpha,12alpha-triol + H(2)O + NADP(+).