Famed lawyer Alan Dershowitz said Sunday reports the FBI had a source giving them information about the Trump campaign is grounds for a investigation.

"Now we have information of an FBI informant in the campaign. That's worth investigation," Dershowitz said during a panel on ABC's "This Week."

"That's good enough to get an investigation going," he continued when told the supposed FBI informant was not a member of Trump's campaign, but that they spoke with up to three campaign aides ahead of the 2016 election.

Two reports published Friday evening, one by the New York Times and the other by the Washington Post, described an FBI source, an a American academic teaching in the United Kingdom, who met with up to three members of the Trump campaign ahead of the 2016 election.

The identify of the FBI informant was leaked to at least two media outlets, but the newsrooms refrained from publishing the individual's name out of concern for national security and the safety of the person and his or her sources. Subsequent reporting has inferred the informant was a Cambridge University professor, who was not embedded in the campaign but sought out meetings with campaign advisers Carter Page and George Papadopoulos, and with Trump campaign co-chair Sam Clovis.

The reports follow Republican furor this week about a possible effort to spy on Trump's 2016 campaign.

Dershowitz, a critic of special counsel Robert Mueller's Russia probe, also condemned political pundits who argue Mueller and former FBI Director James Comey are not biased against President Trump because they had been members of the Republican Party.

"This 'long-time Republican.' Comey was a long-time Republican. They're all long-time Republicans who is hated Trump," he added.

