Russian officials believe that the defective component was damaged during assembly.
It was the third launch of a Soyuz rocket from Russia's northern Plesetsk launch pad this year, the military said.
The Russians have conducted a rapid investigation of the failure, which occurred on October 11, concluding it within three weeks.
Russian cosmonaut Aleksei Ovchinin and U.S. astronaut Nick Hague were aboard the capsule bound for the ISS and were unhurt in the incident, according to reports.
Last week, Russian Federation successfully launched a Soyuz rocket for the first time since the failure.
Sergei Krikalyov, a senior Roscosmos official, was quoted by state news agency Tass as saying the next manned launch had been planned for mid-December, but that Russian Federation was trying to bring the date forward so that the ISS is not briefly left without a crew.
The three crewmembers now on the station will return to Earth Dec. 20, a week later than originally scheduled, Roscosmos officials said.
Ovchinin and Hague returned safely back to Earth in their capsule, and are likely get their chance to go to the space station in the spring, Roscosmos chief Dmitry Rogozin has said.
Roscosmos has scheduled a press conference for November 1 to further detail the outcome of its investigation.
Krikalyov on Wednesday reiterated Roskosmos's earlier statements saying that the malfunction was caused by a collision of the first and second stages of the rocket during the first stage separation.
The Soyuz capsule carrying them separated from the malfunctioning rocket and made what is a steep ballistic descent with parachutes helping slow its speed.
"The reason found by the commission (investigating the accident) was the abnormal operation of a sensor that signals the separation of the first and second stages", Krikalyov said at a space industry event in Moscow.
Russian rockets are manufactured in Russia and then transported by rail to the Russia-leased Baikonur cosmodrome.
Alexander Lopatin, the deputy head of Roscosmos, said that "appropriate law enforcement authorities" will now look into who was responsible for the assembly error.
Since then, Nasa has paid Russian Federation for seats on its Soyuz rockets to ferry its astronauts to the station.