The Power to Punish for Contempt

Two comments responded to my post of yesterday on the prosecution of Florence Hartmann for contempt.
I think it is not correct to say that all criminal tribunals have an inherent power to prosecute contempt. It is probably accurate to say that all criminal tribunals can prosecute contempt when it occurs in the courtroom itself (in facie). But I do not think it is the case that all criminal tribunals have an inherent power to prosecute contempt when it takes place outside of the courtroom (ex facie). In many criminal justice systems this power would be reserved to a court of general jurisdiction, and would not be available to a statutory court. In other words, it is not at all obvious that the Statute of the International Criminal Tribunal gives the judges the power to prosecute contempt when it takes place outside the courtroom.
Now, the judges have given themselves this power by the Rules of Procedure and Evidence, of which they themselves are the authors. But they cannot enact Rules that exceed the powers they have been granted by the Security Council in the Statute.
Assuming they are wrong, who can stop them (other than the Security Council)? How about this scenario. Ms Hartmann refuses to appear, and is then subsequently arrested by national courts somewhere. If she were to challenge her arrest and transfer to The Hague before the national courts, through a habeas corpus application or some similar mechanism, she could raise an interesting argument about the legal validity of the Rules of Procedure and Evidence to the extent that they may exceed the jurisdictional remit in the Statute. In effect, judges of a national court would be asked to sit in judicial review of the powers of the judges of the International Criminal Tribunal for the former Yugoslavia to enact Rules that are ultra vires. Why not?
The idea that international judges have inherent powers to prosecute certain crimes (contempt, perjury) has always bothered me. How far does this go? Can they also prosecute someone for hacking into the website of the Tribunal, or failing to return a book to the library, or stealing the bicycle of one of the judges? I think the answer is that Dutch law would look after that. So why can't Dutch law also deal with contempt and perjury?