Bulgarian media reports said that over the a year ago Marinova had been reporting on an ongoing investigation into alleged corruption involving the misuse of European Union funds by businesses and local politicians, although "it's not clear if Marinova's murder was related to her journalistic work", says CNN.
Bulgaria's prosecutor general, Sotir Tsatsarov, confirmed the arrest of Severin Krassimirov, a 21-year-old Bulgarian citizen, but gave no further details of his location.
The Bulgarian Interior Minister Mladen Marinov described the murder as "exceptionally brutal" and said Marinova was raped before she was murdered, according to state media.
"He has been charged in absence for two crimes - rape and premeditated murder with extreme cruelty", he said.
While Ms Marinova did not appear to have been closely involved in the fraud investigation, her show Detector touched on a sensitive subject in Bulgaria, where corruption is endemic.
It was not clear whether the murder was linked to Marinova's journalistic activities, Balkan Insight reported.
Worldwide, at least 48 journalists have been killed doing their work in 2018, according to the Committee to Protect Journalists, an advocacy group that does an annual count of detained and killed journalists. He declined to answer reporters' question about whether there was signs she had been sexually assaulted.
The body of 30-year-old Viktoria Marinova, identified by authorities only by her initials, was found in a park on Saturday, Ruse's regional prosecutor Georgy Georgiev said.More news: OnePlus 6T event officially locked in for October 30
A journalists' group has called for an investigation into the "brutal" slaying of a Bulgarian television reporter and presenter, but warned against speculating about the motive for her killing.
A TV reporter who covered European Union funds fraud cases was brutally murdered and allegedly raped in northern Bulgaria.
Yordanov said his journalists were getting threats to their safety for this reporting.
And even some of Marinova's fellow journalists were not convinced that she was killed because of her reporting.
The killings of Kuciak in Slovakia and Caruana Galizia in Malta caused alarm across the Continent, coming at a time when a new brand of professed populist leaders in the region have used increasingly caustic language to attack reporters, especially those probing corruption.
Maltese journalist Daphne Caruana Galizia, who investigated local government corruption, was killed in October 2017 by a bomb that destroyed her vehicle.
Her death has shocked and angered many in Bulgaria, where people are frustrated with corruption and an inefficient judiciary that has been criticised by the European Commission.
European Commission spokesman Margaritis Schinas said the commission expected "a swift and thorough investigation" of Viktoria Marinova's death "that will bring those responsible to justice and clarify whether this attack was linked to her work". One participant, Kristina Petkov, said Bulgarians now had "zero" trust in authorities.
The attack has shocked the country and drawn global condemnation amid speculation the murder could be linked to Marinova's work as a journalist. One of them, Kristina Petkov said Bulgarians had "zero" trust in authorities.