The ministry said the activities of the first secretary of the Belarusian embassy violated the status of a diplomat, but refused to make further comments.
The expulsion of the Belarusian diplomat follows a recent incident with a Latvian diplomat in Belarus, who was charged on July 28 with disseminating pornography.
The Belarusian interior minister said at the time that the prosecutor general had sanctioned a search of the diplomat's house, where pornographic materials were found.
"We confiscated the pornographic materials and opened a criminal case against the diplomat on charges of distributing pornography," Naumov said.
The Latvian Embassy in Belarus said in turn, "The search in the diplomat's house was a gross violation of the Vienna Convention [on diplomatic immunity] and international agreements."
The Belarusian Foreign Ministry said that the case would be decided under national legislation and international agreements between Belarus and Latvia.
In April foreign ministers of the 25 European Union member states put Belarusian President Alexander Lukashenko, whom Washington has dubbed as the Europe's last dictator, and 30 other Belarusian officials on a blacklist that bans them from entering the EU.
