National Police Chief Khatia Dekanoidze said, Censor.NET reports citing Interfax-Ukraine.
"At present, four lines of inquiry are being pursued. The motive for the murder is being established. But, unfortunately, no tangible breakthrough has been made," she said at a briefing in Kyiv on Wednesday.
According to Dekanoidze, investigators are currently doing a lot of routine work.
"A very important and time-consuming routine work is underway. We are questioning several hundred people, seizing the surveillance tapes over again that are important for us to watch," LigaBusinessInform quotes Dekanoidze.
She notes it is crucial to grasp the motive behind the murder and start moving in the right direction after that.
As reported, prominent journalist Pavel Sheremet was killed in a car bombing in downtown Kyiv on Wednesday morning, July 20. The incident is preliminary qualified as murder. National Police chief Khatia Dekanoidze said the investigation into the killing of Sheremet would be a matter of honor for her. Kyiv prosecutor Hovda took the probe under personal control. The Information Policy Ministry is set to establish an inter-agency working group to investigate the death of Sheremet. Investigators follow up six versions in Sheremet's killing.
According to witnesses, the explosion occurred when Sheremet stopped at an exit to a main road. They noted high detonation velocity.
The U.S. Embassy in Ukraine extended condolences to Pavel Sheremet's family, friends and colleagues, hoping for a thorough investigation into his death.
Prosecutor General Lutsenko commented on the tragedy: "The death of Sheremet was due to an explosive device. It's a murder." Later, the Interior Ministry added a homemade shell-less explosive device was used, its power equivalent to 600 grams of TNT.
President Poroshenko met with the heads of Ukraine's law enforcement agencies, after which a special investigative group was set up under the leadership of National Police chief Khatiia Dekanoidze. Ukraine has invited FBI and Europol experts to help in the probe. The Security Service will consider the destabilization of the situation in Ukraine as a motive for Sheremet's murder. Meanwhile, Poroshenko asked for a transparent and prompt investigation: "Do not exclude any version. We'll not let anyone open a second front inside the country."
Originally from Minsk, Sheremet was particularly critical of Belarusian president Alexander Lukashenko's crackdown on dissent.
In 1997, the journalist was arrested while reporting about smuggling across the Belarus-Lithuanian border and sentenced to two years in prison - a move widely viewed as politically motivated. Amnesty International declared him prisoner of conscience.
In 1999, Sheremet was presented with the Committee to Protect Journalists' International Press Freedom Award. In 2002, he was presented with the Organisation for Security and Cooperation in Europe's Prize for Journalism and Democracy.
Over the past five years, Sheremet has lived in Kyiv, worked for Ukrainska Pravda and was a host at Vesti radio.
Related materials: Murder of Sheremet