The stadium on the bank of the Vistula river was scheduled to be ready by the end of June, one year before Poland is due to co-host Euro 2012 with Ukraine.
Mikolaj Piotrowski of PL.2012, the firm responsible for co-ordinating preparations for the tournament, was asked if completion of the stadium would be delayed. "Yes, we have identified such risks, as well as some related to quality and security. Key now are talks with the builder that should result in a detailed schedule for fixing this," he told reporters.
"It's too early to speak precisely about exact dates now. There is no risk for Euro 2012 as it is still 380 days ahead of us."
Polish daily Dziennik Gazeta Prawna estimated possible delays of up to 10 months, adding that there were also problems with electricity installations.
On Wednesday, fears about the consequences of future delays - Polish media estimate penalties of above 1 million zlotys ($356,600) per day - dragged down the shares of two Warsaw-listed construction companies,
PBG and Hydrobudowa, that are building the arena in collaboration with Alpine Bau, an Austrian unit of Spain's FCC.
Another new sports venue under construction for Euro 2012, the PGE Baltic Arena in the coastal city of Gdansk, this week lost the right to host a friendly between France and Poland scheduled for June 9 because it was not ready.
