Germany's Federal Criminal Police Office, which was responsible for the operation, confirmed a letter suspected of containing explosives had been destroyed but said whether it actually contained explosives is still under investigation.
The presidential office spokesman said there was no danger to Gauck, Germany's largely ceremonial head of state, who was not on the premises at the time. He spoke on condition of anonymity in line with department rules.
It was not immediately clear where the letter came from. In 2010, a mail bomb was intercepted at Chancellor Angela Merkel's office — part of a spate of parcel bombings for which a Greek anarchist group claimed responsibility.