On June 7, at the Presevo border crossing (between Serbia and Macedonia), a former general of the Security Service of Ukraine (SBU) Oleksandr Naumov was detained:
https://www.carina.rs/pres/vesti/246094/rekordna-zaplena-deviza-na-prelazu-presevo.html

Serbian border guards found more than 600,000 euros, 125,000 US dollars and two emeralds from Naumov.

Naumov did not declare these values.

Together with Naumov, his driver, a German citizen, was detained.

Naumov is the former head of the Main Directorate of Internal Security of the SBU.

Now he is detained by the Serbian police on suspicion of "illicit trafficking in valuable assets."

Naumov could face 12 years in prison.

Alexander Naumov fled Ukraine on February 23, 2022, a few hours before the start of hostilities, together with the head of the SBU Ivan Bakanov.

Bakanov soon returned to Ukraine, while Naumov remained abroad, was stripped of the rank of general in Ukraine and accused of "high treason."

Many observers believe that Naumov, during the investigation, can reveal many secrets of the SBU to the Serbian police.

Including the mechanisms of persecution of dissident Ukrainians.

The Serbian authorities cooperate closely with the authorities of the Russian Federation.