KIEV, Ukraine -- Local authorities in Kiev fear up to 2,000 Champions League final tickets allocated for Real Madrid fans could be sold to Liverpool supporters ahead of Saturday's game in the Ukrainian capital, a source has told ESPN FC.
Due to the difficulties in travelling to Kiev and securing accommodation, almost 2,000 tickets have been returned to UEFA by Madrid.
UEFA president Aleksander Ceferin ruled out the resale of the tickets to Liverpool supporters due to security reasons and the need to ensure proper segregation at the Olimpiyskiy Stadium, which will have a capacity of 63,000 for the match.
The tickets have instead been sold to local football fans in Kiev and, with a substantial number of travelling supporters expected from Liverpool, there are now concerns that the resold tickets may now be sold again to Liverpool fans in the city.
A source told ESPN FC: "It is a worry that the returned Real tickets could end up being sold to Liverpool fans.
"They have been made available to local supporters in Kiev, but it would be naive to think that some of them will not be sold on again to Liverpool supporters."
Liverpool have been given an official allocation of 16,626 tickets for the final, but a greater number of their supporters are expected to travel to Kiev despite flights being cancelled and hotel prices being vastly increased at short notice.
Madrid had the same official allocation -- with around a quarter shared out internally, and 12,802 allocated via a lottery to club members. But many found travelling to and finding accommodation in the Ukrainian capital too difficult or expensive to organise, leading them to either try to sell the tickets to third parties, or return them to the club.
Speaking after UEFA's Exco meeting had awarded the 2020 Champions League final to Istanbul ahead of Lisbon, Ceferin accepted there was a "problem" while defending the way tickets were allocated for the showpiece occasion.
"Unfortunately security reasons prevent us from selling these tickets to Liverpool, it would be too much of a risk," Ceferin said.
"We have a good and fair distribution system, 17,000 each to fans of Liverpool and Real Madrid. The black market is a big problem that we know about. We cancelled [some] tickets that were sold there. We are trying to do as much as possible. There are still people selling tickets and we are looking to correct that."
Amid much criticism of the decision to award the final to Kiev from authorities in Liverpool due to the city's insufficient infrastructure, Ceferin admitted that UEFA were considering the possibility of holding the Champions League decider outside Europe in future.
"It is too early to say anything about that. I mentioned it as a theoretical possibility," he said. "We have to know that the Champions League is a global competition, watched by I think more people outside of Europe than in Europe altogether. So let's see. I can't give you a final answer."
ESPN FC's Madrid correspondent Dermot Corrigan contributed to this report