The death was caused by blows on the head and suffocation, he added.
"Her mobile phone, car keys, glasses and part of her clothes were missing," Georgiev said, adding that prosecutors were probing all leads -- both personal and linked to Marinova's job.
Police sources told AFP that the crime did not immediately appear linked to her work.
The OSCE's media freedom representative Harlem Desir condemned Marinova's killing on Twitter: "Shocked by horrific murder of investigative journalist Victoria Marinova in #Bulgaria. Urgently call for a full and thorough investigation. Those responsible must be held to account."
Local media reported that Marinova was an administrative director of Ruse's TVN television and had just started her own news talk show called "Detector". The channel has not released any statement so far.
Among the most high-profile recent cases were Malta's anti-corruption blogger Daphne Caruana Galizia who died in a car bombing outside her home in October 2017, and top Slovak reporter Jan Kuciak who was shot dead with his fiancee at their home in February.
Widespread corruption, shady media ownership, and suspected collusion between journalists, politicians, and oligarchs have made objective reporting a constant obstacle-run, RSF said.
According to the Bulgaria-based Association of European Journalists, reporters from small regional and local media are particularly subjected to pressure from local businessmen and politicians and outright threats, often leading to self-censorship.
Violence against women has also been widespread in Bulgaria with several brutal killings of women by their ex-boyfriends and ex-husbands causing an outcry in the media recently.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)