Paris attacks suspect Salah Abdeslam exercised his right to silence as he appeared in a French court for his first questioning by the judges investigating the case.
Friday morning’s court hearing at the Palace of Justice in the centre of Paris was not open to the public.
Salah Abdeslam is thought to have played a key role in planning the Paris attacks and transporting the attackers.
The co-ordinated attacks by so-called Islamic State in November killed 130.
Dozens more were severely wounded.
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Salah Abdeslam is being held in the high-security Fleury-Merogis jail just outside Paris.
He was brought to the court amid tight security on Friday morning.
“He did not want to say anything,” his lawyer Frank Berton said after the hearing.
Mr Berton said his client was “particularly disturbed” by 24-hour video surveillance in his cell.
He felt “watched”, the lawyer told France Info. “This does not lead him to co-operate with legal proceedings,” he added.
A lawyer representing some of the victims’ families, Gerard Chemla, said Abdeslam had a moral duty to help the authorities.
“If this man has a conscience, he will co-operate with judicial authorities and will make it so that what happened doesn’t happen again,” Mr Chemla said before the hearing got under way.
France’s inquisitorial justice system means judges are responsible for investigating the case and questioning suspects ahead of any trial.
Salah Abdeslam is being investigated over charges of terrorism-related murder and attempted murder.
Arrested in Brussels in March after months on the run, he was transferred to French custody last month.
His arrest took place just four days before the Brussels bombings and he has been linked to several of the suspects believed to have carried out those attacks.
Belgian authorities have been accused of failing to connect him and his brother, Brahim Abdeslam, to ringleader Abdelhamid Abaaoud.
Brahim Abdeslam blew himself up on 13 November while Abaaoud was killed during a police raid in Paris days afterwards.
The Belgian authorities have already admitted to key blunders in the months leading up to the Paris and Brussels attacks.
And further alleged failings involving Salah Abdeslam were reported by Belgian broadcaster RTBF on Monday.
Separately, one of the suicide attackers at the Bataclan concert hall was buried on Friday morning at a cemetery in his home town in Alsace, according to radio network France Bleu (in French).
The remains of Foued Mohamed-Aggad, 23, were interred in the Muslim section of the cemetery in Wissembourg, with 20-30 police present, the report said.