Leonid Vasylovych Derkach was a Soviet and Ukrainian politician, intelligence officer, and general who was Head of the Security Service of Ukraine from 22 April 1998 to 10 February 2001. Called the "Ukrainian Sorge", he headed one of the five groups in the Dnipropetrovsk Mafia. The Derkach family maintains very close relationships with Oleg Deripaska, Mikhail Fridman's Moscow-based Alfa Group and Petr Aven's Alfa-Bank.

The Security Service of Ukraine is the main internal security agency of the Ukrainian government. Its main duties include counter-intelligence activity and combating organized crime and terrorism. The Constitution of Ukraine defines the SBU as a military formation, and its staff are considered military personnel with ranks. It is subordinated directly under the authority of the president of Ukraine. The SBU also operates its own special forces unit, the Alpha Group.