Speaking two days after Salah Abdeslam was captured during a police raid in Brussels, his lawyer Sven Mary accused the lead French investigator of violating judicial confidentiality.
“I cannot let this pass,” Mr Mary told Belgian state broadcaster RTBF. Mr Mary’s office was not available for comment, but RTBF said that he would start legal proceedings today.
The gun and bomb attacks on a sports stadium, bars, and a concert hall killed 130 people and marked the deadliest militant strikes in Europe since 2004.
Abdeslam admitted to a Belgian magistrate he had planned to take part in a suicide attack at the stadium, and French prosecutor François Molins disclosed this to reporters on Saturday.
At a Paris news conference, Mr Molins read from Abdeslam’s statement: ““He wanted to blow himself up at the Stade de France and, I quote, backed out.”
Mr Molins said people should treat with caution initial statements by the 26-year-old French national.
Abdeslam, who was caught by police in Brussels after an intense, four-month manhunt, spent his first night in a high security prison in the Belgian city of Bruges.
He is due to appear before a judge in Brussels on Wednesday, and RTBF quoted his lawyer as saying he would not seek to have him freed from custody.
Belgian prime minister Charles Michel demanded answers to the question of how Abdeslam managed to evade capture for so long. Belgium’s federal prosecutor has said the fugitive relied on a network of friends and relatives involved in drug dealing and petty crime.
“The immense majority of the population is disgusted by these abject acts against human life... so our investigation must show how he managed to hide from police and security forces,” Mr Michel told RTL.
Separately, Austria’s interior minister Johanna Mikl-Leitner said Salzburg’s judiciary is in contact with France about potentially extraditing two militants with suspected links to the attacks.
Sven Mary, the celebrity lawyer defending Salah Abdeslam https://t.co/WN6XbfA5px— FRANCE 24 (@FRANCE24) March 20, 2016