Why did Belicoff try to kill Nika?

there are plot holes and stuff that doesn't make sense, but essentially.

rogue members of the Russian government wanted to get rid of the current president and put a double in his place. Nika would have intimate knowledge of Belicoff since she was his girfri.... Sex Slave really. Which he most likely acquired from his brother.

The real Belicoff was kill by Agent 47 and the Body Double Belicoff wanted Nika dead!

A rogue faction of the Russian government wanted Belicoff A dead, and a double (Belicoff B) dead. Nika was a sex slave to Belicoff A, not Belicoff B. Belicoff B has to maintain Belicoff A's political life, not necessarily the social (and filthy) life that Belicoff A was maintaining. The sex slaves would probably have a more intimate knowledge of Belicoff A, so they (the rogue faction) probably thought it would make sense to get ride of them (as well as any other associates Belicoff A had, but not covered in the movie).

Basically Belicoff B wanted Nika dead because she had a closer knowledge of Belicoff A when not in the public spotlight than most, and Belicoff B needed to seal the deal. Nika knew too much, like Belicoff B (because of the rogue faction) in general used doubles "like Saddam Hussein." No one else mentioned Belicoff's doubles so that alone meant Nika knew too much.

Can't be too careful with all those weirdos running around.