The Soviet Embassy has protested to the State Department about the treatment of a Soviet correspondent here who the Tass news agency said was arrested Feb. 25 in connection with a traffic offense.

A State Department spokeswoman said last night that she understood that the correspondent. Vitaliy Gan of Falls Church, was taken to the Arlington County Court in handcuffs and was stripped, searched and held in the lockup there. Tass called the searches "degrading."

A magistrate in Rockingham County, Va., said a warrant for Gan's arrest was issued there Feb. 12 after he failed to answer a summons issued last Dec. 1 in connection with an alleged speeding incident.

The magistrate said the warrant charged Gan with failure to appear in Rockingham District Court.

According to the magistrate, persons ticketed for speeding in Virginia generally are given the choice of answering the summons in court or remitting the amount of the fine plus court costs.

A Tass report on the incident called Gan's treatment "outrageous" and a violation of the Helsinki agreements. The report said "official apologies" have been demanded.

Tass said that after his arrest Gan was held in "solitary confinement" until embassy representatives arrived and posted cash bail. A trial date reportedly has been set in early April.

The State Department spokeswoman said Gan apparently had attempted to turn over the ticket to the Soviet Embassy and invoke diplomatic immunity. Gan is not entitled to immunity, the spokeswoman said.