A high-profile Donald Trump supporter has claimed he has evidence that Bill and Hillary Clinton 'murdered' John F Kennedy Jnr because he had planned to run for the same senate seat in New York as the former First Lady.

Roger Stone, who has written books attacking the Clintons in the past, said his next piece of work will prove the involvement of Bill and Hillary in the demise of JFK jnr.

Kennedy was flying his wife Carolyn Bessettee Kennedy and her sister Lauren Bessettein his Piper Saratoga II aircraft on July 16, 1999 when it crashed into the ocean near Martha's Vineyard in Massachusetts.

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Trump supporter Roger Stone, who was a former political aide to Richard Nixon said his new book would feature evidence linking the death of John F Kennedy Jnr in July 1999 to Bill and Hillary Clinton

Roger Stone, pictured, claimed the Clinton's murdered JFK Jnr because he was planning a senate campaign in the same New York seat that had been identified by Hillary and the former first lady feared she would lose

Former President Bill Clinton, pictured left campaigning in Maryland, and Hillary, right, pictured campaigning in New York at separate events have so far not responded to Stone's outlandish conspiracy theory

The National Transportation Safety Board reported that Kennedy lost control of the aircraft in challenging conditions at night while flying over the ocean.

The official report said: 'The pilot's failure to maintain control of the airplane during a descent over water at night, which was a result of spatial disorientation. Factors in the accident were haze and the dark night.'

However, conspiracy theorist Stone claimed: 'I have a book coming up, in which I make the case that John F. Kennedy Jr. was murdered — and he was murdered by the Clintons, because he was in the way. Now, I have extraordinary new evidence that nobody else has seen.'

According to Salon, Stone made the claim to fellow conspiracy theorist James Fetzer.

Stone had previously written 'The Man Who Killed Kennedy: The Case Against LBJ' and 'The Clintons' War on Women'.

In a series of tweets, Stone claimed 'The murder of JFK Jr will be the subject of my next book. JFK Jr was planning on running for NY senate seat @hillaryclinton wanted. Poor b******.'

However, the NTSB, which investigated the crash looked into JFK Jr's flying qualifications.

John F Kennedy Jr, right, and his wife Carolyn, left, along with her sister died in the July 1999 crash

Roger Stone is well known among US right-wing conspiracy theorists for his outlandish claims

He told his fans that his next book will show how Kennedy's plans to run for the senate prompted her move

Kennedy sought weather forecasts and planned to fly to Martha's Vineyard during the day but departed at night. He flew approximately 30 miles over water.

He was a relatively inexperienced pilot with only 310 hours in the cockpit - 55 hours of which were at night.

Experts believe Kennedy, who had only completed about 50 per cent of an instrument rating course, lost his bearings and unable to see the horizon spiraled out of control into the ocean.

Inspectors could not find any prior problems in the aircraft's airframe, systems, avionics and engine which could help explain the catastrophe.

The Clinton campaign has not responded to a request from MailOnline to comment on the allegations.

Earlier, Stone claimed he knew how to guarantee Trump's success in July's Republican convention, preventing the party hierarchy from scuppering the billionaire businessman's presidential plan.

Stone wants to send peasants with pitchforks to the hotel rooms of delegates.

Appearing on a podcast, Stone claimed he wanted to 'disclose the hotels and the room numbers of those delegates who are directly involved in the steal.

Kennedy was flying in a Piper Saratoga II when he lost control of the aircraft and spiraled into the ocean

'If you're from Pennsylvania, we'll tell you who the culprits are. We urge you to visit their hotel and find them,' he said on Freedomain Radio.

'You have a right to discuss this if you voted in the Pennsylvania primary, for example, and your votes are being disallowed.

Stone, a longtime aide to the late U.S. president Richard Nixon, was a Trump insider until early August when he left the real estate tycoon's campaign, but has been an outspoken supporter ever since.

His books include a lengthy expose of 'The Clintons' War on Women' and a nonfiction title that explores whether President Lyndon Johnson had John F. Kennedy killed.

He was also the only person quoted last month in a National Enquirer story that linked Trump rival Sen. Ted Cruz with allegations of five extramarital affairs.

Cruz vehemently denied the charges, and openly questioned whether Stone and Trump ever really parted ways.

'Roger Stone remains the henchman, the hatchet man, the enforcer for Donald Trump,' the second-place White House hopeful said March 27 on 'Fox News Sunday.'

'He’s pushing these attacks. And by the way, he’s been pushing them for many months.'

President Bill Clinton, left, invited JFK Jr, right, into the Oval Office several times while president

A Trump spokesperson did not immediately respond to a request for comment.

Stone sketched out a scenario in Monday's interview that would see Trump falling short of the 1,237 delegates he needs in order to clinch the presidential nomination before the Cleveland, Ohio convention.

'If Trump does not run the table on the rest of the primaries and the caucuses, we're looking at a very, very narrow path in which the kingmakers go all out to cheat, to steal, and to snatch this nomination from the candidate who is overwhelmingly selected by the voters,' he told host Stefan Molyneux.

'I have urged Trump supporters: come to Cleveland. March on Cleveland. Join us in the Forest City,' Stone continued. 'We're going to have protests, demonstrations.'

Media Matters for America, an aggressive liberal message group that tracks news reports and interviews which are favorable to Republicans, first surfaced the interview on Tuesday.

The Republican National Committee has said no plot exists to sideline Trump, pointing instead to an established procedure that could throw open a 'contested' convention to a floor fight for delegates if the billionaire fails to cinch the prize on the first vote.

As Cruz makes headway, winning state-level elections and deploying a strong ground game to collect delegates in states without traditional popular voting, Trump's window for an early victory has become progressively more narrow.

Should the Texas senator claim a majority of delegates in Wisconsin on Tuesday, for instance, Trump would need to win more than 56 per cent of the remaining delegates that are up-for-grabs in order to reach his goal before the July convention.