Russia, traditionally a close ally, has said the detained men were merely transiting via Belarus en route to a third country and had no plans to try to influence Belarusian domestic politics.
A 69-year-old woman was arrested in connection with the murder.
Footage released by the FSB security service showed Ivan Safronov being detained outside his Moscow flat by armed agents.
Meir Ben-Shabbat and Russian Security Council Secretary Nikolai Patrushev held a discussion over the phone regarding efforts for combating the spread of the coronavirus pandemic.
Earlier this month, police in the Russian Far East charged Julia Tsvetkova, an LGBT and feminist activist, with spreading pornography via her pictures, she said on her Facebook page.
Rumors were abound that the alligator may have spent some years as part of Adolf Hitler's personal collection.
The exhibit features works by the likes of prominent Soviet artists such as Ilya Arons and Valery Ginzburg, who were both Jewish.