The Paris attacks trial continued on Thursday with Belgian police giving evidence on the terrorist career of Oussama Atar, mastermind of the November 2015 murders that cost 131 people their lives. Atar himself is presumed dead in a coalition air raid in Syria in 2017.
Tension remains high between the court in Paris and the witnesses in Brussels.
Several legal teams at the special criminal court have criticised the Belgian investigators for their refusal to testify in person. Brussels says anonymity is essential to protect the officers' security.
Some in Paris think they are staying away to avoid being too harshly questioned on their supposed mishandling of key aspects of the Paris attacks case.
An article published on Thursday by the French news website Mediapart clearly says "the Belgian police are struggling to cover the mistakes they made in 2014 and 2015 while the network which would lead to the Paris attacks was being put in place."
Trouble with televised testimony
In practical terms, the court has heard a week of testimony from a series of figures on television screens. The pictures come from Brussels. The problem is that the questions which follow each presentation are not always answered to the satisfaction of Paris.
"I didn't work on that file," "I was not involved in that investigation," "I don't have the information to answer that question," are some of the phrases which have been repeated by the anonymous witnesses in Brussels. The fact that each officer is accompanied by a legal representative and a Belgian judge adds to the sense in Paris that a sort of state censorship is in operation.
Several of the 14 prisoners on trial have boycotted the hearings in protest at the decision by Brussels, refusing to take their places in the high-security box reserved for the accused.
'This is not a trial of the Belgian police'
On Thursday, it all got a bit too much for the tribunal president, Jean-Louis Périès.
"Listen to me. This is not the trial of any institution or any police service," he reminded the court after a particularly confrontational exchange, his normally benevolent eyes glinting darkly.
"There have been commissions of inquiry in both France and Belgium. We know, sadly, that mistakes were made, that people slipped through the net. That has been established for some time now.
"But we are not here to evaluate the merits of the Belgian authorities in the way they handle the fight against terrorism. That is simply not our job."
Embarrassing questions about Atar
The case of Oussama Atar does, nonetheless, give rise to some difficult questions.
Atar was a celebrity in Islamic State ranks in Syria.
He fought the Americans in Iraq after the Bush-Blair invasion; he took part in the battle of Fallujah; he was imprisoned by US forces in Abou Ghraib.
Despite that remarkable background, he had no difficulty in obtaining a Belgian passport less than 12 months after his return to Europe. He had spent eight years in some of the most notorious jails in the Middle East, prisons which were the breeding ground of the whole Islamic State project.
But he was never placed under police supervision by Brussels, nor made the subject of any special investigation, despite being on an Interpol terrorist watchlist. The Belgian police file on Oussama Atar was opened on 14 November 2015, the day after the Paris attacks!
He was arrested in 2013 by the Tunisian police acting on the Interpol warning. They sent him back to Belgium. But Atar was able to leave Brussels unhindered on a flight to Turkey barely one month later. He never came back.
It has been alleged, in the French press and in a book called "The Clandestine Islamist", that Atar's passport application was approved by the Belgian police because they thought he would work for them as a spy inside the IS terrorist operation.
"Is this true?" asked the French Attorney General on Thursday, apologetically.
"I don't have any information on that point," was the predictable answer from the televised witness.
The trial continues.