A magistrate at the centre of a trial France's president called a "disaster" has insisted he acted correctly.
Burgaud said other magistrates rubber-stamped his decisions
Fabrice Burgaud, whose inquiries led to several innocent people being jailed on paedophilia charges, defended his actions to a parliamentary inquiry.
Lawyers say he questioned the three chief suspects together, allowing them to fabricate stories about a paedophile ring in the northern town of Outreau.
Thirteen people, including a priest, were eventually acquitted.
One suspect committed suicide while in detention.
Much of the evidence given by children during the trial was found to be inconsistent and a number of experts were discredited.
President Jacques Chirac called the trial an "unprecedented judicial disaster".
Mr Burgaud carried out the pre-trial investigations in the case.
In testimony carried live on French television, he told French deputies that no-one had warned him he was on the wrong path.
Looking tired and drawn, he told the panel he was acutely aware of the victims' suffering, but insisted that he had done his job dutifully.
May 2004: Trial starts in St Omer of 17 suspects
Late May 2004: Suspect Myriam Delay clears 13 of the accused, but then re-accuses them
2 July 2004: 10 convicted and seven acquitted
1 December 2005: Six acquitted on appeal. Two couples serving up to 20 years in jail
The judge, 34, said other magistrates had rubber-stamped his decisions.
"I know this has shocked people... but I repeat that I believe I did my job honestly without taking sides in any way," Mr Burgaud said.
However, in an opening statement to the panel, he admitted that he had "perhaps" made "errors of appreciation".
Christian Godard, one of those acquitted in the case and who attended the hearing, said: "It will do me good to go to see him. I'm not going to speak to him, to say anything to him, but I'm going to show him I'm not scared."
The cross-party committee of 30 French MPs is looking into ways of reforming the French justice system.