The criminal investigation involving wacky “trial by combat” lawyer Richard Luthmann is moving at a snail’s pace, one alleged victim complains.

An attorney for Janine Materna complains that the victims of Luthmann — who allegedly impersonated political rivals online — have yet to be questioned by a special prosecutor tapped two months into the probe.

“As a former prosecutor . . . if this case were assigned to me, the first call I would make is to the victims(s). Yet, you did not attempt to contact Ms. Materna prior to our conversation, which was approximately one month after your appointment,” Andrew Stengel said in an Oct. 25 letter to Thomas Tormey, the special prosecutor.

Luthmann — an eccentric Staten Island attorney who once challenged a rival lawyer to a trial by combat — has been accused of posting false comments in the name of political opponents on Facebook. He denies the claims.