BIRMINGHAM, Ala. -- Weeks after he published a book about the brutal slaying of Emmett Till, a North Carolina author received a call from FBI agents asking about his interview with a key witness who acknowledged lying about her interactions with the black teen. Not long after that, Duke University scholar Timothy Tyson said he turned over interview recordings and other research materials for his 2017 book on the 1955 case that shocked the nation and helped build momentum for the civil rights movement.

Hours after news broke Thursday that the government was reopening its investigation into the case, prompted by the book, Tyson told reporters that he supports a fresh look at "one of the most notorious racial incidents of racial violence in the history of the world," but doesn't think his research alone will provide enough evidence for new charges.

"It's possible that the investigation will turn up something. But there's nothing that I know of, and nothing in my research, that is actionable, I don't think," he said. Still, he said investigators may be able to link it to other material in their possession.

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Tyson's 2017 book "The Blood of Emmett Till" quotes a white woman, Carolyn Bryant Donham, as saying during a 2008 interview that she wasn't truthful when she testified that the black teen grabbed her, whistled and made sexual advances at a Mississippi store six decades ago.

"She said with respect to the physical assault on her, or anything menacing or sexual, that that part isn't true," Tyson told "CBS This Morning" last year.

A federal official familiar with the matter told The Associated Press that information in the 2017 book was what led federal investigators to re-examine the case. The official wasn't authorized to discuss the matter publicly and spoke to AP on condition of anonymity.

The reopening of the Till case was disclosed in a federal report sent to lawmakers in March that said the Justice Department had received unspecified "new information." The report's contents weren't widely known until Thursday.

The case was closed in 2007, with authorities saying the suspects were dead.

The prosecutor with jurisdiction over the Mississippi community where Till was abducted, District Attorney Dewayne Richardson, declined to comment on whether federal authorities had given him new information since they reopened the investigation. The Justice Department also declined to comment.

It's unclear what new charges could result from a renewed investigation, said Tucker Carrington, a professor at the University of Mississippi law school.

Conspiracy or murder charges could be filed if anyone still alive is shown to have been involved, he said, but too much time likely has passed to prosecute anyone for other crimes, such as lying to investigators or in court.

Two white men -- Donham's then-husband, Roy Bryant, and his half brother, J.W. Milam -- were charged with murder but acquitted in the slaying of the Chicago teen, who had been staying with relatives in northern Mississippi at the time. The men later confessed to the crime in a magazine interview but weren't retried. Both are now dead.

Donham, who turns 84 this month, lives in Raleigh, North Carolina. A man who came to the door at her residence declined to comment about the investigation.

Deborah Watts, co-founder of the Emmett Till Legacy Foundation, said it's wonderful her cousin's killing is getting another look but declined to discuss details, saying: "None of us wants to do anything that jeopardizes any investigation."

Abducted from the home where he was staying, Till was beaten and shot, and his body was found weighted down with a cotton gin fan in a river. His mother, Mamie Till Mobley, had his casket left open to show the world what had happened to him. Images of his mutilated body gave witness to the depth of racial hatred in the Deep South and inspired civil rights campaigns.

Donham, then 21 and known as Carolyn Bryant, testified in 1955 as a prospective defense witness in the trial of Bryant and Milam. With jurors out of the courtroom, she said a "nigger man" she didn't know took her by the arm in the store.

"He said, 'How about a date, baby?'" she testified, according to a trial transcript released by the FBI a decade ago. Bryant said she pulled away, and moments later the young man "caught me at the cash register," grasping her around the waist with both hands and pulling her toward him.

A judge ruled the testimony inadmissible. An all-white jury acquitted her husband and the other man even without it.

In the book, author Tyson wrote that Donham told him her testimony about Till accosting her wasn't true.

"Nothing that boy did could ever justify what happened to him," the book quotes her as saying.