Can ibid. be used under the Harvard referencing style?
From the examples at the University of the West of England:


  Generally ibid. and op.cit. tend to be used more in the body text for the Harvard system, and more in the reference list for the numeric system, as you can see.


They also note:


  There is no single authority that defines the 'Harvard' referencing style. Please seek guidance on the preferred scheme of referencing from your home institution or the journal in which your study will appear.


So I'm going to say yes, there is no reason as to why you couldn't use ibid with the Harvard citation style.