"I have published documents today about the surveillance on two German diplomats," Bezsonov told Russia's Channel One broadcaster.
"One of them is an employee of the German embassy in Ukraine, and the other one is a very interesting person since he is a representative of the Trilateral Contact Group of the Normandy format, an economic adviser."
He added that he posted videos of the surveillance on the diplomats.
"I want to stress that there are many similar videos of other diplomats as well, including videos from their hotel rooms and other places, following them from places where they live, from the restaurants they go to. Of course, not all of the materials will be published for obvious reasons," Bezsonov said.
The SBU has been "collecting dirt on their so-called 'partners' in order to manipulate them," Bezsonov said, adding that the service also spied on and attempted to recruit employees of the Organization for Security and Cooperation in Europe (OSCE).
The latest comes months after the Belarusian State Security Committee had also detailed in late March that officials had taken down a Ukrainian spy network implemented under a diplomatic cover. At the time, reports indicated that eight of the 19 diplomats stationed at Belarus' Ukraine embassy had been deemed spies.
Although tensions have remained elevated under the Biden administration, matters were kicked up a notch after Russia launched its special military operation in Ukraine. The US and its allies have in turn heightened disputes by moving to supply Ukraine with heavy financial and military support. Although US officials have indicated Washington does not intend to dispatch weaponry that will "allow Ukrainians to attack Russia," reports have suggested the US may send precision-guided missiles.