Presenting a nine-page written statement at the trial in Arlon, southeast Belgium, Dutroux's lead lawyer Xavier Magnee insisted that his client could not have acted alone in the abductions, rape and murders of several girls.
"Can people make you believe that there wasn't a paedophile ring? Would we be the only country in the world where paedophiles are isolated perverts?" Magnee told the court on the second day of hearings in the long-awaited trial.
He said police forensic analysis had found traces of DNA from "a least two or three unknown people" in the dungeon-like cellar at Marcinelle, near the southern town of Charleroi, where Dutroux allegedly held six girls captive.
Four of the girls died, and two were rescued, in a sequence of discoveries in August 1996 that traumatised Belgium.
Opinion polls suggest that nearly 70% of Belgians are convinced that Dutroux was part of a broader paedophile network than the four people on trial in Arlon - Dutroux himself, his wife, a drug-addict friend and a businessman.
"We see clearly in the (prosecution) dossier material proof that other people than the accused here present frequented the cellar at Marcinelle at the same time as the victims," Magnee said.
"The jury is only being presented with selected slices of the case."
The lawyer also returned to an allegation - dismissed by prosecutors as groundless - that a satanic cult was involved in the girls' abductions.
Police in August 1996 found a note at the home of Bernard Weinstein, an accomplice who Dutroux has admitted murdering, which led them to investigate the "Abrasax" organisation led by "high priestess" Dominique Kindermans.
The Belgian press at the time speculated that the organisation was a devil-worshipping sect that procured young girls for human sacrifices at black masses.
Police, however, dismissed the apparent lead and said there was no evidence against Kindermans to warrant such allegations.
The defence team also urged the court to consider the disappearance, in sometimes violent or suspicious circumstances, of several witnesses they said could shed better light on the fate of two eight-year-old girls who allegedly starved to death in Dutroux's dungeon.