"From what we see, there are about 15 (of cases) with possible involvement of Burisma, or Biden, or Zlochevski, or Kurchenko, but I cannot say that those we see or understand now are all cases. We continue to audit and review," Riaboshapka declared during a press conference broadcast on the Nash channel.
The prosecutor added that his office is studying the files that have been filed, or fragmented or examined before, in order to make a decision in the event that some procedural irregularities are discovered.
Joe Biden's youngest son, Hunter, joined the board of directors of the Ukrainian gas company Burisma Group in May 2014, a few weeks after his father, at that time vice president of the United States, made an official visit to Ukraine.
In 2016 the then general prosecutor of Ukraine, Victor Shokin, began investigating this company for corruption. After his dismissal, in March of the same year, the legal proceedings against Burisma Group were closed.
In 2018, Joe Biden publicly admitted to threatening Kiev to withdraw $ 1 billion in US loan guarantees if Shokin, whom the West had repeatedly accused of turning a blind eye to corruption, remained in office.
The involvement of the Biden in Ukraine was at the center of media attention on suspicions that US President Donald Trump would have pressured his Ukrainian colleague, Vladimir Zelenski, to investigate the son of the former vice president and today presidential candidate of the Opposition Democratic Party for the 2020 elections.
The US House of Representatives initiated a process of political trial against Donald Trump following a complaint about it.
For its part, the White House published the official transcript of the telephone talk that the US president had with Zelenski on July 25.
The text shows that Trump repeatedly referred to the Biden case in that conversation.
However, both the US president and his Ukrainian colleague deny that there was pressure.