Republican presidential candidate Ted Cruz has denied all claims made by a newspaper that his father helped Lee Harvey Oswald distribute leaflets promoting Fidel Castro's communist regime in 1963.

The National Enquirer published photos of John F Kennedy's killer, claiming to have concrete evidence the man beside him is Cuban-born Rafael Cruz.

On Saturday, the Republican nominee blasted the new claim linking his father's Castro activism to Lee Harvey Oswald, branding it 'garbage'.

'This is another garbage story in a tabloid full of garbage,' Cruz's communications director Alice Stewart told the Miami Herald. 'The story is false; that is not Rafael in the picture.'

A newspaper article claims this man (circled) is Rafael Cruz. The man on the far right is Lee Harvey Oswald, who is seen distributing propaganda about Fidel Castro's communist regime in New Orleans in 1963

It would not be the first link between the elder Cruz and Castro; Ted (pictured together) said last year that his father tried to join Castro's guerrilla army during the 1950s revolution. But he has never been linked to Oswald

The images, released by the US government amid an investigation into JFK's 1963 assassination, show Oswald and a group walking around a street in New Orleans in 1963 handing out leaflets to passers-by.

They were used as evidence against New Orleans-based Oswald, who was murdered by Jack Ruby days after the Dallas shooting, in an investigation into the president's death. But the man in the white shirt beside him was never identified.

It would not be the first link between the elder Cruz and Castro; Ted admitted last year that his father tried to join Castro's guerrilla army during the 1950s revolution which overthrew the Batista regime in 1959. But he has never been linked to Oswald.

Photo experts sought out by the newspaper compared the images to pictures of Rafael Cruz at the time to find similarities.

'There’s more similarity than dissimilarity... it looks to be the same person and I can say as much with a high degree of confidence,' Mitch Goldstone, president and CEO of ScanMyPhotos, told the Enquirer.

The Cruz campaign claims it is 'garbage' that Rafael Cruz (pictured in January campaigning for his son) was involved with Oswald. The elder Cruz wrote in his January book about trying to fight for Castro in Cuba

'They seem to match,' Carole Lieberman, a University of California - Los Angeles forensic psychiatrist, told the Enquirer.

The images were the only source of evidence the newspaper cited for its May 2 cover story headlined 'Ted Cruz Father Now Linked to JFK Assassination!'

The Enquirer has officially endorsed Donald Trump, and wrote a defense for the story, claiming an anonymous tipster approached the editorial team with the images.

'In this instance, we believe American voters have a right to know the truth about the Cruz family,' the defense read.

The National Enquirer published a story last month that speculated about five women with whom the Republican presidential candidate was rumored to have had extramarital affairs.

He has called the claims 'complete garbage' and on April 4 told Fox News: 'I have always been faithful to my wife.'

The statement was almost a week after he had first been asked by Daily Mail Online whether he could make clear he had never cheated.

Asked directly to 'tell us on the record that you've never been unfaithful to your wife?' Cruz dodged the question and attacked Trump.

Oswald seen handing out the leaflets that read 'hands off Cuba' a few years after Castro's guerrilla army overthrew the Batista regime

Cruz said the story was 'total lies' and was 'planted by Donald Trump's henchmen'.

Cruz's evangelical faith has been central to his campaign and he has contrasted his family values with those of Trump.

In his 2015 book A Time For Truth, Texas senator Ted Cruz writes that, after his Cuba-born dad was briefly jailed for urban insurgent activities, he asked if he could join Castro at his mountain camp.

He says his father couldn't reach Castro, and instead fled to Texas, eventually renouncing Castro after he took power in 1959 and declared himself communist.

His father had already admitted to the connection, and provided more detail in his book A Time For Action released this January.

'The U.S. government was duped,' he wrote.

'The American people were duped. I was duped. When people ask me why I supported Castro in over-throwing the Cuban government, I readily admit that I didn’t realize he was a communist.'