Can the closure and liquidation of a bank, which is considered an exercise of police power, be the subject of judicial inquiry?

Yes. While the closure and liquidation of a bank may be considered an exercise of police power, the validity of such exercise of police power is subject to judicial inquiry and could be set aside if it is either capricious, discriminatory, whimsical, arbitrary, unjust or a denial or due process and equal protection clauses of the Constitution (Central Bank v. CA, G.R. No. L-50031-32, July 27, 1981).