A private investigator has claimed that Seth Rich – a murdered Democratic National Committee staffer at the heart of numerous conspiracy theories – was the source of emails leaked to WikiLeaks.

Police in Washington DC maintain that Rich, 27, was killed as a result of a botched robbery. However former investigator Rod Wheeler claims he has sources within the department that suggest otherwise.

Appearing on Fox 5 in Washington, Wheeler alleged that Rich is "absolutely" the WikiLeaks source and said that information on his laptop would verify the claim.

"The police department nor the FBI have been forthcoming," he said.

"They haven't been cooperating at all. I believe that the answer to solving his death lies on that computer, which I believe is either at the police department or either at the FBI. I have been told both."

Wheeler went further to suggest that there was a wider cover up, however no independent information could verify that claim.

"I actually have a source in the police department that has looked at me straight in the eye and said, 'Rod, we were told to stand down on this case and I can't share any information with you.'

"Now that's highly unusual for a murder investigation, especially from a police department."

Wheeler's claims follow other threads which seem to suggest that Rich was linked to WikiLeaks and the Podesta Emails leak, which threw the 2016 presidential race on its head.

One of which is a conversation between hacker Guccifer 2.0 and Playboy model Robbin Young, where Rich was identified as the "whistleblower".

WikiLeaks founder Julian Assange himself has also previously implied that Rich was the source of the leaks, but did not go as far as identifying him.

Fake news, say Rich's family

Following Wheeler's claims, Rich's family have distanced themselves from the investigator who they are said to have hired.

"As we 've seen through the past year of unsubstantiated claims, we see no facts, we have no evidence, we have been approached with no emails and only learned about this when contacted by the press," they said in a statement.

"Even if tomorrow, an email was found, it is not a high enough bar of evidence to prove any interactions as emails can be altered and we've seen that those interested in pushing conspiracies will stop at nothing to do so.

"We are a family who is committed to facts, not fake evidence that surfaces every few months to fill the void and distract law enforcement and the general public from finding Seth's murderers.

"The services of the private investigator who spoke to the press was offered to the Rich family and paid for by a third party, and contractually was barred from speaking to the press or anyone outside of law enforcement or the family unless explicitly authorised by the family."