Should archaeologists take artefacts from Egyptian tombs?

This is something of a moral dilemma.

On one side of the argument there is much to be learned from the artefacts from ancient people. In addition to which much of the treasure found was accumulated by uncivilised acts and through conquest and slavery. So could be seen as returning these items to the public.

On the other side it could be classed as grave robbing. If we are to put a time limit on what may or may not be taken who then decides that time limit and what should it be?

100 years. 1000. 3000.

It is difficult to reconcile all points but many believe the knowledge gained outweighs the possible desecration of a grave.