Comment on the calculation of the angular momentum and mass for the (anti-) self-dual charged spinning BTZ black hole

A recent paper [M. Kamata and T. Koikawa, Phys. Lett. B 353 (1995) 196] claimed to obtain the charged version of the (2 + 1)-dimensional spinning BTZ black hole solution by assuming a (anti-) self-dual condition imposed on the electric and magnetic fields. We point out that the angular momentum and mass diverge at spatial infinity and as a consequence the solution is unphysical.