The Seattle Times says a 21-year-old Washington State woman told authorities the 51-year-old Copperfield raped her over the course of two days at his exclusive 150-acre Bahamas resort.
She also contends he struck her, and then threatened her before putting her onto a plane.
Copperfield's lawyer David Chesnoff said in a statement, "This not only unfairly and falsely defames my client, but it undermines the integrity of the entire investigation."
"I think this leak is unfortunate and I think it is shocking because it came from, according to the report, no less than three law enforcement sources," legal analyst Rikki Klieman told CBS correspondent Jeff Glor.
The Early Show legal analyst Mickey Sherman said the system simply broke down and Copperfield's attorney is justified in his outrage. Leaking information like this ruins the entire legal process, he said.
The report says the accuser told investigators she and her family were approached by a member of Copperfield's entourage at a January performance on the West Coast. They were given special seats and she was selected to come on stage.
She said Copperfield later told her he could help with her modeling career and that she should come to his secluded retreat. She agreed but when she returned home, she says she was examined at a sexual assault center and filed a police report.
"David Copperfield is in a very difficult position here," Klieman said. "He's rendered impotent; no pun intended."
A week and a half ago the FBI searched Copperfield's warehouse and a casino hotel in Las Vegas, taking a digital camera and computer hard drive. Copperfield has not been charged with a crime, and Chesnoff says his client never forced himself on anyone.
Sherman said if he were Copperfield's attorney, he would advise him to speak up and defend himself, because now that the leak has occurred, every part of the accuser's story will be called into question, especially the fact that she didn't make a complaint until arriving home in Seattle.
"He is a public figure," Sherman said. "He is a communicator, an entertain entertainer, in front of thousands of people a day. Even though it's not the legally correct thing to do, he should say I'm getting screwed here."