WASHINGTON -- Soviet listening devices have been discovered in other allied embassies in Moscow in addition to the network of more than 40 microphones found in the U.S. Embassy recently, officials reported today.
They said the attempts to "bug" the other embassies had been made over the years but declined to identify the allied countries, the types or devices or the dates of their discovery.
At the same time, the State Department sought to determine whether any sensitive or secret U.S. information had been significantly compromised by the carefully concealed Russian eavesdropping.
The 40 microphones were found buried deep in the U.S. Embassy, the Department disclosed yesterday.
Officials declined to clear up speculation whether a recent Soviet defector, Yuri I. Nossenko, provided information leading to the discovery of the 40 microphones.
Nossenko, identified as a Soviet secret police agent stationed in Geneva, defected February 4 and was brought to Washington for questioning.
In February, the State Department recalled one of its security technicians from Moscow for conferences which led to a decision to demolish a room in the Moscow Embassy in April. The microphones were found in the course of the demolition.
When asked about Nossenko, authorized U.S. officials would say only that it is routine practice to . question defectors concerning possible attempts to penetrate U.S. security.
Officials said that from time to time eavesdropping devices have been found in other U.S. embassies in Eastern Europe.
There was no indication whether any of these were of the same type as those found in Moscow or that they were as heavily concealed .in the structures.
The bizarre network of listening devices apparent- . ly had been there since 1952 or 1953, and presumably were installed when the Russians remodeled the ; building for American occupancy in 1952. The United States has leased the embassy building since May, 1953.
The Department said some of the microphones were found on the floor where Ambassador Foy D. Kohler has his office. Kohler delivered what was described as a strong, formal protest to the Soviet government yesterday.