The Bulgarian authorities believe that her murder was sexually motivated rather than an attempt to suppress anti-corruption journalism and this morning the country's interior minister announced that Severin Krasimirov, 21, had been held in Germany and charged with her killing. The prosecutor said the suspect of Russian origin was taken into custody in Germany.
Teodor Atanassov, the chief police officer of the northern town of Ruse, told reporters the man - who has not been identified - would be freed "very shortly".
Ruse Regional Prosecutor Georgi Georgiev told state media that Marinova's mobile phone, vehicle keys, glasses and part of her clothing were missing when her body was found.
The suspect was arrested on Tuesday (local time) at the request of Bulgaria, interior minister Mladen Marinov told a news briefing attended by Mr Borissov and the country's chief prosecutor.
Authorities said she died from blows to the head and suffocation. She had been raped, beaten and suffocated.
Mr Biro said he had never met Ms Marinova, but one of her colleagues had interviewed him and Mr Stoyanov about their work.
Earlier, in February 2018, Slovak journalist Jan Kuciak and his fiancée were shot dead as Kuciak was investigating fraud involving businessmen with Slovak political ties, and suspected mafia links of Italians with businesses in Slovakia.
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The murder case has shocked fellow journalists and sparked global condemnation, with Ms Marinova now the third European reporter to have been killed in the past year.
And even some of Marinova's fellow journalists were not convinced that she was killed because of her reporting. The collected evidence so far pointed to a spontaneous attack and sexual assault, he said.
The Commission urged Bulgaria to conduct a rapid investigation and the US embassy said it was shocked by the "horrific murder".
"Shocked by the horrendous murder of Victoria Marinova".
Prosecutors said late on Monday that they had opened an investigation into the suspected misuse of European Union funds, as police investigate the rape and murder of Ms Marinova, whose strangled body was found on Saturday dumped near the Danube River.
Bulgaria has fallen to 111th place in the 2018 World Press Freedom Index and has ranked last among all European Union nations, according to Reporters Without Borders.
The European Commission has urged Bulgaria to conduct a rapid investigation into the murder. "Bulgarian authorities must employ all efforts and resources to carry out an exhaustive inquiry and bring to justice those responsible".