US President Donald Trump mounted an angry defense of Supreme Court ­Justice Brett Kavanaugh on Sunday as the controversial judge faced calls for an investigation, or even impeachment, over fresh allegations of sexual misconduct. 

Trump blasted the media and "Radical Left Democrats" after a former Yale classmate of Kavanaugh alleged that the jurist - one of the most senior judges in the land - exposed himself at a freshman year party.

The latest allegation in The New York Times came after Kavanaugh denied sexual misconduct accusations leveled against him by two women during his confirmation to the Supreme Court in October.

"Now the Radical Left Democrats and their Partner, the LameStream Media, are after Brett Kavanaugh again, talking loudly of their favorite word, impeachment," Trump tweeted. "He is an innocent man who has been treated HORRIBLY. Such lies about him. They want to scare him into turning Liberal!"

The new allegations came from Max Stier, who runs a nonprofit in Washington. His concerns were reported to the FBI during Kavanaugh's 2018 confirmation process but not investigated, according to the Times. 

Stier said he saw his former classmate "with his pants down at a different drunken dorm party, where friends pushed his penis into the hand of a ­female student." 

Stier has not spoken publicly about the incident but his story was corroborated by two officials, the Times said.

It is the latest in a string of accusations of unwanted sexual contact or assault against Kavanaugh since Trump nominated him to the Supreme Court.

Christine Blasey Ford testified before Congress that Kavanaugh sexually assaulted her in the 1980s, while Deborah Ramirez told The New Yorker that Kavanaugh had waved his penis in front of her face at a 1980s dormitory party.

The latest allegation surfaced during a 10-month investigation by Times reporters Robin Pogrebin and Kate Kelly, and features in their upcoming book, The Education of Brett Kavanaugh: An Investigation. 

Trump called on Kavanaugh to take legal action over the claims, suggesting also that the Department of Justice should intervene on the judge's behalf and "come to his rescue." 

But Democrats seeking to be Trump's opponent in the 2020 election said the judge should be investigated - and three of them called for his impeachment.