The two men are suspected arms dealers and allegedly part of an Albanian gang involved in weapons smuggling. They are among a group of 11 suspects detained three months ago. Following the arrests, Audenaert held a press conference praising the intensive year-long enquiry carried out by police, which culminated in an action in which 180 police swooped on 22 different locations and netted firearms and ammunition, explosives, police uniforms and bulletproof vests.

According to the lawyer for one of the men: “It was written in the stars that something like this would happen one day.” Under Belgian procedure, each accused man must be brought every two weeks to court to have his detention prolonged. At that time and for 48 hours afterwards, the case-file has to be put at their disposal for consultation by defence lawyers.

There are 11 suspects in this case, each with a different timetable for appearing in court. Each time an appearance is scheduled, the increasingly voluminous case file has to be brought to the office of the clerk of the court in the Justice Palace in Brussels, from the office of the investigating magistrate in the building across the street. There is only one copy, which in this case is in almost constant transit from one office to another.

It has now emerged that two of the men were not given access to the dossier two weeks ago. This is a breach of the law and led to their release.

In normal circumstances, the prosecution would appeal to the court, the dossier would be opened up to the defence 48 hours before that appeal was heard, and everything would return to normal. However, in this case, the hearing was scheduled for 14 May – and 13 May was a public holiday. The file should have been available from 11 May, but an official forgot about the holiday, with the result that the file arrived too late.

Outgoing justice minister Stefaan De Clerck said he would be asking for an explanation. “A magistrate ought to be flexible regarding these details so that every mistake doesn’t lead to a release,” he said. “But this is not something that can be sorted out in five minutes.”