Former CIA director Allen Dulles ordered JFK's assassination because he was a 'threat to national security', a new book has claimed.

Journalist David Talbot insists the head of the 'most potent agency' during the Cold War wanted the former president 'removed' for the 'good of the country'.

It is just one of the allegations he makes against Dulles who was in charge when the CIA overthrew governments, invaded Cuba and were implicated in political assassinations.

In The Devil's Chessboard: Allen Dulles, the CIA, and the Rise of America's Secret Government, Talbot states Dulles and his brother John Foster Dulles, the Secretary of State under Dwight Eisenhower, helped undermine American democracy.

Shocking allegations: Former CIA director Allen Dulles (right) ordered JFK's (left) assassination because he was a 'threat to national security', a new book has claimed.

The founder and editor-in-chief of Salon.com also said Dulles 'undermined or betrayed every president he served,' and sensationally suggests he may be involved in murdering one of them.

Talbot also claims that Dulles tried to make a deal with Nazi Germany in the last days of the Second World War that would see Hitler out, but some of the Third Reich would be in place.

Dulles, he suggests, also oversaw a CIA program that conducted extremely dangerous experiments on the human brain.

He was interested in finding out whether 'LSD could be used to program zombielike saboteurs or assassins.'

Talbot writes: 'Washington was gradually taken over by business executives, Wall Street Lawyers, and investment bankers.

'During the Eisenhower administration, the Dulles brothers would finally be given full license to exercise their power in the global arena.

'In the name of defending the free world from Communist tyranny, they would impose an American reign on the world enforced by nuclear terror and cloak-and-dagger brutality.

'The Dulles brothers would prove masters at exploiting the anxious state of permanent vigilance that accompanied the Cold War.

He adds: 'The Allen Dulles story continues to haunt the country. Many of the practices that still provoke bouts of American soul-searching originated during Dulles's formative rule at the CIA

'Mind control experimentation, torture, political assassination, extraordinary rendition, mass surveillance of U.S. citizens and foreign allies—these were all widely used tools of the Dulles reign.

Journalist David Talbot insists the head of the 'most potent agency' during the Cold War wanted the former president 'removed' for the 'good of the country'. Kennedy is pictured presenting the National Security Award to Dulles in Virginia in 1961

Dulles became the first civilian Director of Central Intelligence in 1952 under Eisenhower. He illustrated coups in Iran and Guatemala, putting pro-American governments in place.

However the disastrous Bay of Pigs and the perception that the new CIA-backed regimes were brutally and corrupt led to a drop in his popularity.

He was eventually dismissed under Kennedy and replaced by John McCone. Dulles was later appointed to the Warren Commission that investigated the assassination.

President Kennedy was shot and killed by a sniper in Dallas in 1963. Lee Harvey Oswald was the prime suspect, but many conspiracy theories have increased suspicion others may have been involved.

The Warren Commission concluded it was the work of a 'lone gunman' - but doubts have been cast over the findings.

McCone was the director of the CIA when Kennedy died. It therefore means Dulles would have had to return to the CIA two years after he retired to orchestrate the plot.

But Talbot insists there was a 'consensus' in the agency that 'for the good of the country, he must be removed. And Dulles was the only man with the stature, connections and decisive will to make something of this enormity happen.'

In The Devil's Chessboard: Allen Dulles, the CIA, and the Rise of America's Secret Government, Talbot states Dulles and his brother John Foster Dulles, the Secretary of State under Dwight Eisenhower, helped undermine American democracy

His suggestions underline the pitfalls of the Warren Commission - that suggested a lone gunman was behind the assasination.

But he doesn't offer a plausible alternative.

Last week a report claimed McCone withheld information about the assassination.

The CIA reports, which were declassified last fall, claim that then-agency head John McCone and other top officials were part of a 'benign cover-up' surrounding the assassination of Kennedy in November 1963.

The report's author, CIA historian David Robarge, claims McCone withheld information to keep the Warren Commission focused on what the agency believed to by the 'best truth… that Lee Harvey Oswald, for as yet undetermined motives, had acted alone,' according to Politico.

McCone and others were 'complicit' in keeping 'incendiary' information from the Warren Commission, a group established in the days after Kennedy's assassination by President Lyndon B Johnson to investigate the incident.

The investigators were officially known at the President's Commission on the Assassination of President Kennedy.

McCone, who was appointed by Kennedy, died in 1991. His testimony in front of the commission, including Chief Justice Earl Warren, was considered vital in finding out what led to Kennedy's death.

The former CIA head concluded in his assessment that Oswald, a former Marine, was a 'lone gunman' who acted on his own.

The Warren Commission's final report - after a year-long investigation that included testimony from hundreds of other witnesses - was consistent with McCone's assessment.

The commission also reviewed FBI and Secret Service reports, visited the crime scene in Dallas and analyzed Oswald's records as part of their investigation.

The 888-page report found that Kennedy was killed from a gunshot wound while riding in a motorcade passing below a school book depository building, where Oswald worked.

Many people, however, are unconvinced that Harvey acted alone in the assassination and believe he was part of a bigger conspiracy.

Within an hour of Kennedy being shot, Oswald killed a police officer who had stopped to question him and was arrested minutes later.

He was murdered the next day while being transported to a jail with higher security and his motives were never revealed.

While the declassified CIA reports did not raise question about the findings of the Warren Commission, including that Oswald was the gunman, the reports acknowledge the failure in the CIA's dealings with the Warren Commission.

Talbot also claims that Dulles tried to make a deal with Nazi Germany in the last days of the Second World War that would see Hitler out, but some of the Third Reich would be in place. Dulles, he suggests, also oversaw a CIA program that conducted extremely dangerous experiments on the human brain

The moment JFK is struck by an assassin's bullet as he travels through Dallas in a motorcade on November 22, November 1963