Alan Dershowitz said Special Counsel Robert Mueller's investigation of President Trump and his campaign is like Captain Ahab's pursuit of the White Whale in the American classic "Moby Dick."
"You give a prosecutor one goal ... it's unlikely he's going to want to come away with nothing," the Harvard law professor told "Fox & Friends" Saturday.
"They're determined to get that white whale."
Mueller widened the scope of the Russia probe this week to include the president's personal finances, a move that prompted President Trump to warn that such investigation was in “violation” of the intended scope.
"A general search into his financial records to look for a crime is not right," Dershowitz said.
New reports also uncovered a possible conflict of interest with some of Mueller's staff, who gave Democrats large sums up to almost $33,000.
President Trump did not say whether he would fire Mueller for pursuing matters "unrelated to Russia."
“I can’t answer that question because I don’t think it’s going to happen,” Trump said.
"We don't want America ever to become a country where prosecutors are determined to find something on somebody," Dershowitz said.