Authorities have already determined that pipe bombs, found in a garage rented by Beate Zschäpe, were built with TNT stolen in 1991 from the army depot in Großeutersdorf, a small town in Thuringia, according to a report from Bild am Sonntag.
Zschäpe, now in custody, was a member of the so-called National Socialist Underground, a neo-Nazi terror group suspected of murdering at least 10 people.
Investigators now think that the remaining explosives may be in the hands of the neo-Nazis. Federal authorities are investigating whether a nail bomb that exploded in Cologne in 2004 was made with the stolen material.
Andre E., a suspect in the crimes, was asked about this immediately after his arrest on Thursday, but refused to speak, the newspaper said.