The Foreign Affairs Ministry has told BBC Sinhala Service that the case would not affect Brig. Fernando in any way.
The case relates to an alleged throat-slitting gesture made by Brig. Fernando to Tamil protesters in front of the high commission on 04 February last year.
Helen Mowatt of the Public Interest Law Centre that appears for the complainants said there were two witnesses who had seen the military officer making that gesture.
Foreign Ministry spokesperson Saroja Sirisena said diplomatic immunity would prevent Brig. Fernando from being taken before courts.
She said no decision has been taken yet whether the government should make legal representations on behalf of him.
Meanwhile, Army spokesman Brig. Sumith Atapattu said the Army had not been informed about a case being filed against the former defence attache in London.