A covert listening device (bug) was concealed inside a wooden gift of America’s Great Seal given by Russia to the United States Ambassador to the Soviet Union, on August 4, 1945. Although not reported then, the device was extensively investigated and imitated by US spies.
In May 1960, the listening device was mentioned during a meeting of the United Nations Security Council that had been convened by the Soviet Union after a U.S. U2 spy plane had entered their territory and been shot down.
The U.S. ambassador Henry Cabot Lodge Jr. showed off the bugging device in the Great Seal to illustrate that spying incidents between the two nations were mutual and to allege that Nikita Khrushchev had magnified this particular incident as a pretext to abort the 1960 Paris Summit that was intended to discuss the crisis situation in Berlin.
Source: Wikipedia