President Donald Trump's high-profile election attorney has been barred from testifying at a Tuesday hearing in Michigan.

Rudy Giuliani will not be allowed to testify at Tuesday's Michigan Senate Oversight Committee hearing because he does not have "first-hand knowledge" of election fraud, Republican Chair Ed McBroom told correspondent Jonathan Oosting.

The hearing is expected to focus on voting irregularities in Detroit.

Giuliani has recently appeared at non-official meetings with Republican legislators in Pennsylvania and Arizona.