Only a few days after a bombshell hit the Seth Rich murder investigation in Washington, D.C., with a recording of Pulitzer Prize-winning investigative journalist Seymour Hersh pointing out that WikiLeaks stopped releasing hacked DNC emails when Rich died, a private investigator is asking Special FBI Counsel Robert Mueller to look at the circumstances.

Rich's murder in 2016 has never been solved. He was near his home in Washington early in the morning when he was shot in the back twice. Police described it as a robbery, but neither his watch nor his wallet was taken.

He had been working for the Democratic National Committee at a time when emails from the organization were being handed over to WikiLeaks for publication.

On Tuesday, lobbyist and lawyer Jack Burkman sent a letter to Mueller, who was appointed to review the allegations against Trump's campaign in 2016 of collusion with Russia, urging him to expand his work.

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

Rich, Burkman explained, could be the "missing link."

"(A)s director of The Profiling Project (TPP), the independent, nonpartisan group investigating the murder of Seth Rich, I am formally asking that the special counsel widen its investigation to include this case," Burkman wrote. "The murder of Seth Rich may be the 'missing link' that connects otherwise incongruent events relating to Russia collusion in the 2016 presidential election."

WikiLeaks' Julian Assange, in an August 2016 interview, appeared to suggest that Rich was one of his sources.

WND also reported Rod Wheeler, an investigator who has worked on the case, filed a lawsuit alleging President Trump conspired with Fox News to concoct a fake news story that it was Rich who leaked DNC emails to WikiLeaks. Wheeler claims the White House was attempting to deflect from the Russia probe.

If you would like to see more investigative reporting about the unsolved murder of Seth Rich, consider supporting WND’s project through its GoFundMe campaign.

Wheeler alleges that several players concocted a false narrative and tried to spread false news about the murder. And Wheeler claimed Trump knew of the false statements and tried to spread false news, according to the London Daily Mail.

But White House Press Secretary Sarah Huckabee Sanders said Trump "had no knowledge" of Fox News’ Seth Rich story.

Nonetheless, Wheeler’s complaint, filed in the Southern District of New York, alleges the defendants "worked together to create a false narrative surrounding the death of Rich."

Meanwhile, Rich's family members say they are "devastated" by the frenzy surrounding the murder and the increased attention brought by the new lawsuit. Family spokesman Brad Bauman and the Rich family declined to respond to WND's requests for comment on the lawsuit.

On Tuesday, Burkman offered to assist the special counsel by revealing the evidence he has accrued since launching the Profiling Project and offered to testify under oath.

"Since forming TPP, my team and I have become a clearinghouse for an array of tips and information related to the case," the letter states. "Based on multiple pieces of confidential, verifiable information we received at TPP, coupled with allegations asserted in the Rod Wheeler v. TWENTY-FIRST CENTURY FOX, INC., FOX NEWS NETWORK LLC filed last Tuesday in New York, I believe there is sufficient evidence to warrant the special counsel's involvement. We will share what we know and I am willing to testify under oath."

Burkman, president of a lobbying firm in D.C., is offering a $105,000 reward for information leading to the arrest of Rich's killer. He launched the Profiling Project in March, an "all-volunteer group of current and former George Washington University forensic psychology graduate students and instructors."

As WND has reported, Seth Rich, 27, the DNC's voter expansion data director, had accepted a position with Hillary Clinton's campaign just before his death. On July 10, he was fatally shot in Washington, D.C., near his apartment in an affluent neighborhood. His wallet, credit cards, watch and phone were left in his possession. The Metropolitan Police Department has described the murder as a "botched robbery."

More than a year later, no suspects have been named, and no one has been arrested.

On July 22, 2016, just 12 days after Rich's death and days before the Democratic Party Convention in Philadelphia, WikiLeaks began publishing "44,053 emails and 17,761 attachments" from top DNC officials. Some of the emails showed DNC officials conspiring to sabotage Bernie Sanders' candidacy and help secure the party nomination for Hillary Clinton and resulted in the resignation of former DNC Chairwoman Rep. Debbie Wasserman Schultz.

In the Hersh audio, the investigative reporter claims an FBI report described to him by an insider confirms that Rich had taken some emails to WikiLeaks and requested payment for a full trove of DNC emails during the presidential campaign.

Hersh points out that the DNC emails obtained by WikiLeaks stopped pouring in after the mysterious murder.

In fact, the latest DNC email released by WikiLeaks was dated May 18, 2016 – just weeks before Rich was murdered.

"There are no DNC or Podesta emails that exist beyond May 21 or 22, last email from either one of those groups. What the report says is that some time in late spring … he makes contact with WikiLeaks, that's in his computer," Hersh says in audio almost certainly recorded by financier Ed Butowsky, who hired private investigator Wheeler to investigate the murder.

Hersh continued: "Anyway, they found what he had done is that he had submitted a series of documents – of emails, of juicy emails, from the DNC."

On the audio recording, Hersh says his information came from a source "on the inside," a "very high-level guy" who is "unbelievably accurate and careful." He said WikiLeaks was able to acquire access to a password-protected dropbox that contained the emails.

Hersh also claims the DNC invented a story alleging Russian "hacking," with help from CIA Director John Brennan, as a cover story.

If you would like to see more investigative reporting about the unsolved murder of Seth Rich, consider supporting WND’s project through its GoFundMe campaign.