"We are analysing what police learned yesterday from witnesses," Guido Busch, a spokesman told news agency AFP. "We have no hot leads."
Busch could not say how much the four robbers got away with in the heist that occurred at around 2:15 pm on Saturday, but reports ranged between €250,000 and €800,000.
Police investigations are continuing and more witnesses would likely be interviewed later Sunday, Busch added. He said he was "optimistic" that analysis of video footage taken from the hotel would lead to clearer pictures of the robbers.
In what was described by Berlin-based daily Der Tagesspiegel as "the most spectacular raid for years," the gang, armed with handguns and machetes, burst into the Grand Hyatt hotel, threatening security staff and sparking a panic.
Images of the chaotic scenes during the raid were broadcast by the NTV television station, showing furniture overturned and poker players hiding under tables and trying to escape.
Amid the chaos, one of the security guards managed to tear a bag full of cash from the robbers. Seven people sustained minor injuries in the crush.
Interviewed in Der Tagesspiegel, the guard said, "I just wanted to protect the money. You don't think of anything in that situation, just your duty."
He said the attack had happened while two of his colleagues were away on a break, "which suggests the thieves planned the attack very precisely."
Another witness interviewed in the paper was less impressed with the robbers. "In my opinion, these guys weren't pros. It's crazy to run around here with a samurai sword. Professionals would have shot once in the air and not run around like headless chickens," he said.
Witnesses said the whole incident lasted less than 10 minutes and the gang fled out into the streets around Potsdamer Platz, one of Berlin's busiest squares.
The guard said: "You lose all sense of time in that situation. It seemed like an eternity. Even in the evening, I was still pumped up with adrenaline."
The organisers, the European Poker Tour (EPT), said the one-million-euro event resumed "within a few hours."
A statement on their website called on anyone with photo or video footage of the robbery to hand it over to police. The tournament's final table was due to start play at 12:00 pm. The competition started on Tuesday with nearly 1,000 players, including German tennis legend Boris Becker.
"American online phenomenon Kevin 'ImaLuckSac' MacPhee was already a massive chip leader when the interruption took place and there was no looking back once play resumed," the EPT website said.
MacPhee "currently has 6,070,000 in chips, more than a million clear of his nearest rival, Ketul Nathwani from Britain."