Kaviarovitch is a Syldavian police agent who appears in King Ottokar's Sceptre in The Adventures of Tintin series. He is charged with keeping an eye on Syldavian nationals based abroad who are plotting to overthrow the state. Kaviarovitch's cover is that of an artist.
He is first seen following Tintin in the street after the latter has been to a Syldavian restaurant in Brussels which Kaviarovitch knows is used as a meeting place for Syldavian dissidents.
Back at home, Tintin receives a phone call from an unknown man arranging a meeting in Tintin's flat for later that day. When the doorbell rings, Tintin opens the door only for Kaviarovitch to collapse unconscious in front of him presumably following an assault by Sporovitch and/or other plotters.
When he recovers, Kaviarovitch has no idea who he is or why he is in Tintin's flat. Tintin assumes his memory loss to be genuine and has him taken to a doctor.
Tintin later gets access to a notebook which includes a photo of Kaviarovitch and background information. The page includes the word LIQUIDATED, indicating that he has been murdered.