Kozlov, 41, who oversaw bank licensing and led efforts to close down dozens of banks for violations of banking legislation, particularly for money laundering, died September 14 after being shot the day before along with his driver.
"The person who ordered the murder of Andrei Kozlov, the first deputy chairman of the Central Bank, was arrested early on January 11," the office said in a press release, declining to reveal the suspect's name.
Prosecutor General Yury Chaika announced in early December that the high-profile murder had been solved, and that a number of suspects had been arrested in the course of the investigation.
His office said Thursday a total of seven people, including the suspected mastermind of the murder, have now been arrested.
Banking chief murder (full topic)