Who is at Topčider?

A few months ago, two young soldiers were killed at the Topčider military base in Belgrade under circumstances that have not been explained to anybody's satisfaction. The media speculation that surrounded the incident included revelation of a secret underground complex that had been built at the site during the Tito period. Today B92 reports that Ratko Mladić's chief bodyguard, one captain Branislav Puhalo, commands the Guard Brigade at Topčider, a fact which military people seem to be denying but would seem to be normally a part of public record. Nobody seriously doubts that the military is protecting Mr Mladić. So is he the secret that is being guarded at Topčider?