The author of a book about Hillary Clinton and Vince Foster, the aide whose death in 1993 was ruled a suicide, says Clinton triggered Foster's death by bullying him unmercifully, calling him out from among his colleagues as a failure.

The claim comes from Ronald Kessler, formerly an investigative reporter with the Wall Street Journal and the Washington Post, and the author of "The First Family Detail: Secret Service Agents Reveal the Hidden Lives of the Presidents and The Secrets of the FBI."

Kessler wrote about his claim in the London Daily Mail on Thursday.

The controversies surrounding Foster's death have re-surfaced more than two decades later with Hillary Clinton's Republican presidential rival Donald Trump calling Foster's death "fishy" and saying the issue should be taken "very seriously."

TRENDING: Alan Dershowitz sues CNN to halt 'malicious' attacks on innocent people

WND reported one week ago that Hillary Clinton repeatedly tried to reach Foster on his final day.

Hillary for prosecution, not president! Join the sizzling campaign to put Mrs. Clinton where she really belongs

She had asked her chief of staff three times to contact Foster and have him call her. But she has never been asked why she was so eager to talk to Foster on the day he turned up dead in Fort Marcy Park outside of Washington, D.C., on July 20, 1993.

Trump's charge is that Foster "had intimate knowledge of what was going on."

"He knew everything that was going on, and then all of a sudden he committed suicide."

In the Daily Mail, Kessler wrote, "FBI agents investigating the death of Bill Clinton's Deputy White House Counsel found that Hillary Clinton 'triggered' his suicide when she attacked and humiliated her mentor from their former Rose Law Firm in front of other White House aides a week before he took his own life."

He noted the FBI investigation was conducted for independent counsel Kenneth W. Starr's probe of the Clintons' investments in the Whitewater real estate development.

"For unknown reasons, Starr elected to conceal the FBI's findings in his final report," Kessler wrote.

"But in interviews for my book 'The First Family Detail,' the FBI agents revealed the truth about Foster's death on July 20, 1993, when he shot himself at Fort Marcy Park along the Potomac River."

Get the hottest, most important news stories on the Internet – delivered FREE to your inbox as soon as they break! Take just 30 seconds and sign up for WND's Email News Alerts!

He said the interviews revealed that Hillary Clinton had held a meeting in the White House with Foster and others to talk about Hillarycare.

"Hillary violently disagreed with a legal objection Foster raised at the meeting and ridiculed him in front of his peers, former FBI agent Coy Copeland and former FBI supervisory agent Jim Clemente told me," Kessler wrote.

"During the White House meeting, Hillary continued to humiliate Foster mercilessly, both former FBI agents say. 'Hillary put him down really, really bad in a pretty good-size meeting,' Copeland says. 'She told him he didn't get the picture, and he would always be a little hick town lawyer who was obviously not ready for the big time.'"

Kessler added, "Indeed, Hillary went so far as to blame Foster for all the Clintons' problems and accuse him of failing them, according to Clemente, who was also assigned by the FBI to the Starr investigation and who probed the circumstances surrounding Foster's suicide.

"'Foster was profoundly depressed, but Hillary lambasting him was the final straw because she publicly embarrassed him in front of others,' says Clemente, speaking about the investigation for the first time," Kessler wrote.

Kessler also reported that Clemente said, "Hillary blamed him for failed nominations, claimed he had not vetted them properly, and said in front of his White House colleagues, 'You're not protecting us' and 'You have failed us.'"

Kessler says Foster's behavior changed dramatically.

On July 20, Foster "left the White House parking lot at 1:10 p.m," Kessler wrote. "The precise time when he shot himself could not be pinpointed. After Park Police found his body, they notified the U.S. Secret Service at 8.30 p.m."

He continued: "No one can explain a suicide in rational terms. But the FBI investigation concluded that it was Hillary's vilification of Foster in front of other White House aides, coming on top of his depression, that triggered his suicide about a week later, Copeland and Clemente both say."

However, a subsequent investigation into the death did not mention those circumstances, Kessler said.

Foster served as deputy White House counsel for the first few months of the Bill Clinton administration and was part of the core group that followed the Clintons from Little Rock, Arkansas, to Washington. He had known Hillary for years, working with her at the Rose Law Firm in Little Rock.

Hillary for prosecution, not president! Join the sizzling campaign to put Mrs. Clinton where she really belongs