Harvard Law professor emeritus Alan Dershowitz said Sunday that Dr. Anthony Fauci was legally entitled to invoke the Fifth Amendment during a recent Senate hearing despite receiving a presidential pardon, and argued that Congress can obtain his testimony by granting him immunity from prosecution.

Speaking on Newsmax's "Sunday Agenda," Dershowitz said Fauci's attorneys handled the matter properly. "I would have advised him exactly the way he was advised," Dershowitz said. "He was still vulnerable for being prosecuted for anything that he did or said after the pardon came into effect. So he had years of exposure, and his lawyer gave him the right advice to take the Fifth, and his lawyer gave him the right advice to take the Fifth 111 times."

Dershowitz explained that a witness cannot selectively answer some questions on a subject while invoking the Fifth Amendment on others. "You can't take the Fifth once and then answer questions, turn the spigot on and turn the spigot off," He said. "The Supreme Court has held over and over again that once you start answering questions on a subject, you can't suddenly invoke the Fifth."

While acknowledging potential political consequences, Dershowitz maintained the decision was legally sound. "Any good lawyer, Republican, Democrat, conservative, liberal, would have given him the same advice and would have told him that he's going to come off looking terribly," Dershowitz said.

He recommended lawmakers pursue immunity rather than contempt proceedings. "Give him immunity," Dershowitz said. "We should be more interested in getting at the truth and transparency than we should in pointing fingers of blame. So give him immunity and then he won't have any Fifth Amendment right."

Dershowitz noted Congress has the authority to immunize Fauci from federal prosecution and potentially state-level cases as well. "If Congress wants the information, there's a way of doing it," Dershowitz said. "But I think they want the show as much as they want the information."