A student at Princeton University who said he was beaten unconscious by two black-clad assailants Friday has said that he fabricated the assault, and that he sent e-mail death threats to himself, three other Princeton students, and a prominent conservative professor at Princeton, Robert George, police said today.

No charges have been filed against the student, Francisco Nava, pending further investigation, a spokesman for the Princeton Township Police said.

In an interview, Mr. George earlier described Mr. Nava's wounds as "severe," doubting that they could have been self-inflicted.

Over the weekend, Mr. Nava's jaw was badly swollen, his face was covered with cuts and abrasions, and the inside of his mouth was bleeding, Mr. George said after visiting Mr. Nava in the emergency room.