Czech team leader Frantisek Fojt and team doctor Petr Sikora told a news conference at the Olympic Stadium on Friday that Sebrle and his team mate Tomas Dvorak, the 1996 Olympic bronze medallist, were given glucose, which is not banned.
"We did not use any forbidden substances as glucose is not a forbidden substance," Sikora said. "During extreme conditions the body's glucose level falls, and by applying the glucose you can get the level back to normal."
In a statement on Friday the International Association of Athletics Federations (IAAF) said it had been told by the Finnish team that two Czech athletes had received intravenous infusions before the start of the decathlon 1,500 metres.
IAAF spokesman Nick Davies confirmed that the athletes were world record holder Sebrle, who won a world silver medal behind American Bryan Clay on Wednesday, and Dvorak.
"Intravenous infusions are prohibited if they are intended to alter the integrity or validity of an athlete's sample," the IAAF statement said.
"Each of the athletes was tested following the end of the 1,500 metres event. The results are not yet known but the IAAF can confirm that neither sample was diluted."
He said decathletes were sometimes injected during the two-day event to replace lost nutrients.
"I wouldn't say it's common but it is done," he said. "There is no offence if the sample is not diluted."
Sikora added that it was the first time Sebrle had received glucose as an emergency solution.
"The athletes stayed in the rest rooms during the whole competition and never went anywhere else to take forbidden substances," said Fojt.
The IAAF has asked the Czech team a number of questions about the infusions and expects to receive replies later on Friday or early on Saturday.
"The Finnish team have asked us to do something and we are not happy anyway that they (the Czechs) were treating the athletes in front of others in the combined changing room," said the IAAF's Alonso.
"We are waiting for their explanation, we will study it. The present situation is that there is no doping violation."
(Additional reporting by Oliver Grassman)