Where, in an investigation concerning one of the crimes or offences falling within the scope of Articles 706-73 and 706-73-1, knowledge of this information is likely to seriously endanger the life or physical integrity of a person, the members of his family or his close relations and that it is neither useful for the determination of the truth nor essential for the exercise of the rights of the defence, the liberty and custody judge, seised at any time by reasoned request from the investigating judge, may, by reasoned decision, authorise that the following do not appear in the case file:
1° The date, time and place where the technical means mentioned in article 230-32 was installed or removed;
2° The recording of location data and the elements that make it possible to identify a person who took part in the installation or removal of the technical means mentioned in the same article.
The decision of the liberty and custody judge referred to in the first paragraph of this article shall be attached to the record of the proceedings. The information referred to in 1° and 2° shall be recorded in another record, which shall be placed in a file separate from the proceedings file, in which the request from the examining magistrate provided for in the first paragraph shall also appear. This information shall be entered in a register, which shall be opened for this purpose at the judicial court and which shall be marked and initialled.