Defender Artem Fedetskyy has denied a newspaper story that Ukraine left cigarette butts and beer cans in their dressing room following their Euro 2016 loss to Germany.
The German newspaper Bild has published an article, which is accompanied by pictures, detailing what it claims are the two dressing rooms following Sunday's match in Lille.
In the piece, there are images of beer cans, discarded cigarette butts and a bottle of wine in the Ukrainians' facility while the room which was occupied by the Germans, who won 2-0, is in pristine condition.
However, ahead of Thursday's game with Northern Ireland in Lyon, defender Fedetskyy dismissed any suggestions his team had been smoking and drinking alcohol.
"I was in the changing room, please believe me, there was nothing like that,'' the 31-year-old said.
"We are a normal team. We have no players who drink beer. I think the information is wrong. I'm not really interested in it because I know my players, I know my teammates and nothing happened like that. Maybe someone wants to provoke us.
"Please believe me, we are a very disciplined team. We behave in a civilised way, not only in Ukraine but also in other countries. You can look for the DNA from the cigarettes!''
Both Northern Ireland and Ukraine lost their opening fixtures at the weekend, meaning Thursday's Group C game has huge implications for the two nations' qualification hopes.
Fedetskyy, like his teammate Ruslan Rotan, has highlighted the physical nature of Michael O'Neill's side and has warned his colleagues to be mindful at set-piece situations.
"We watched Poland against Northern Ireland, we analysed the game and they are a very good team that plays strong, physical football,'' Fedetskyy said.
"We have witnessed that they fight to the end. It's not going to be easy tomorrow but we have our own type of football, our own tactics.
"I think we will play on the top, put our own opponent under pressure. This game will be difficult but we have our aim and I hope that tomorrow's match will be positive for us.
"We are keen to play tomorrow, we want to put things right, we lost against Germany and tomorrow we want to earn our first victory. I think we can do it.
"It is going to be a decisive match for both teams.
"They are very dangerous from set pieces, that's why we have to play with maximum focus, we have to defend compactly and we will have to convert all chances that we will get.
"It is a decisive match and we have to focus 100 percent for all 90 minutes.''