Any decision appointing experts must set a time limit for them to complete their assignment.
If special reasons so require, this time limit may be extended at the request of the experts and by a reasoned decision issued by the magistrate or court that appointed them. Experts who do not submit their report within the time limit set for them may be replaced immediately and must give an account of the investigations they have already carried out. They must also return within forty-eight hours any objects, exhibits and documents entrusted to them in the performance of their duties. They may also be subject to disciplinary measures up to and including removal from one or other of the lists provided for in Article 157.
Experts must carry out their mission in liaison with the investigating judge or delegated magistrate; they must keep him informed of the development of their operations and put him in a position to take any useful measures at any time.
The examining magistrate, in the course of his operations, may always, if he considers it useful, be assisted by the experts.