Dalek 4 (The Only Good Dalek)

A Dalek drone captured by the Space Security Service during the 41st century in a war against humanity and the New Dalek Paradigm and placed on Station 7. It was later one of ten captive Daleks, itself numbered 4, apparently reconditioned to defend the station against a Dalek force that invaded the station in search of "the Abomination" where it was rendered inactive. Dalek 1 was destroyed in the battle. (COMIC: The Only Good Dalek)

Behind the scenes
Dalek 4 is not actually referred to as such in The Only Good Dalek. However, during the process of "converting" the station's captive Daleks, Jay orders them all numbered and designates a Dalek Scientist as Dalek 1. It can be safely assumed that this pattern was continued with the other nine Daleks.