A Soviet citizen allegedly working as an agent for the U.S. Central Intelligence Agency has been seized here along with unspecified documents purportedly implicating members of the U.S. Embassy staff, the government newspaper Izvestia reported tonight.

In a brief, back-page announcement, Izvestia identified the man as Y. A. Kapustin. It did not name any of the American diplomats who allegedly controlled his espionage activities.

A spokesman for the U.S. Embassy declined to comment.

Izvestia said Kapustin was arrested by agents of the KGB, the Soviet secret police, who found in his possession "espionage assignments, codes and instructions on the maintenance of secret communications" equipment. The newspaper did not report that any such equipment was seized, but it said that KGB agents also discovered "other materials that indisputably prove Kapustin's espionage work with CIA representatives who operate under the guise of staff members of the U.S. Embassy in Moscow."

Espionage is a capital offense in the Soviet Union. Last year, a Soviet engineer identified as B. Nilov was convicted of spying for the United States after he allegedly was recruited by the CIA in Algiers in 1974. He was said to have been trained by the CIA there before returning to the Soviet Union. His sentence was not reported.

An earlier such incident involved Anatoly N. Filatov, who was convicted of being an American spy in 1978 and sentenced to be shot by a firing squad. The sentence was commuted to 15 years in prison.

Tonight's report gave no indication of Kapustin's profession or the date of his arrest. It said only that he worked at a Moscow enterprise.

Izvestia said that an investigation of the Kapustin case was continuing, but it did not indicate whether the American officials allegedly linked to the man are still in Moscow.

Last month, the Soviet government expelled a junior British diplomat on espionage charges, apparently in retaliation for the expulsion of an alleged Soviet spy from Britain two months ago.

No other details on the Kapustin case were available here.