As prosecutor Jacek Węgrzynowicz from the District Prosecutor's Office in Tarnobrzeg informed on Monday, the investigation were extended, inter alia, due to difficulties in interrogation one of the witnesses who is currently in one of the European countries. His questioning is necessary for the investigation. Therefore, the prosecutor's office will use the legal assistance of the country in which the witness is staying, or will use the witness's possible visit to the country, e.g. for holidays. The investigation into the suspected acceptance of financial benefits by Warsaw officials has been conducted for over three years by the Tarnobrzeg district prosecutor's office, which at the end of February 2017 - by the decision of the National Prosecutor Bogdan Święczkowski - took over the proceedings from the Regional Prosecutor's Office in Warsaw.