Kenneth Starr was a well-known lawyer and a former federal appellate judge.
Starr passed away on Tuesday at a hospital from complications following surgery at the age of 76.
Starr spent around four months in a Houston hospital's intensive care unit.
Bill Clinton was impeached as a result of his criminal investigation.
Starr joined President Donald Trump's legal team in 2020 as he prepared a defence for his own impeachment trial.
For a long time, Starr's excellent legal reputation seemed to set him on a road to the Supreme Court.
Mitch McConnell, the Republican leader in the Senate and a Kentucky native, expressed his sorrow upon learning of Judge Ken Starr's passing on Tuesday.