The envelope “was delivered to the government office today,” the PM’s press service said, adding that the Office for the Protection of Constitutional Officials and Diplomatic Missions is currently examining the parcel.
"Police officers from the relevant unit under the Bratislava Regional Police Department are looking into the matter," said Michal Seiff, a spokesman for the regional police.
On July 6, Fico made his first public appearance since he was seriously wounded in an assassination attempt on May 15 while greeting supporters near the Slovak parliament building in Handlova.
The Slovak Prime Minister was in serious condition but not in immediate life-threatening danger. He sustained two to three gunshot wounds in the abdomen, with around five shots fired in total, Plus Jeden Deň reported.
Photos of the suspect surfaced later, leading to the arrest of 71-year-old Juraj Cintula, an author and supporter of the opposition party Progressive Slovakia.
The shooter expressed his discontent with the Slovak government's policies, Denník N and Refresher reported.
Doctors performed surgery on Fico on the night of May 16, ensuring his condition was stabilized and not life-threatening.