Alexander Torshin, Deputy Speaker of the Federation Council, the upper house of parliament, said: "I think this will take place in early September, when members of the State Duma [lower house] and senators return after the parliamentary recess."
The commission was earlier expected to release the report on investigations into the terrorist attack at a school in Russia's southern republic of North Ossetia at the end of the spring parliamentary session in mid-July.
The three-day Beslan hostage-taking crisis in September 2004 has been subject to several independent investigations conducted by the Prosecutor General's Office, the parliamentary commission, an unofficial commission of local legislators, and an initiative group of people affected by the massacre.
Mothers of children killed or injured in Beslan have complained about a lack of progress and inconsistencies in the investigation. They also accuse security forces of provoking the explosion in the gym, which led to chaos and the deaths of many hostages.
Special services stormed the besieged school on the third day of hostage-taking, after an explosion in the gym where hundreds of children, parents and teachers had been kept without any food or water.
The Prosecutor General's Office said in June it was extending the investigation until January 1, 2007.
Official reports said 331 people, including 186 children, were killed in the school.
