He has been accused of being everything from a racist to a misogynist in recent months as his bid for the White House has gained support across the U.S., but one question could yet prove more damning: is Donald Trump a Russian agent?

While the answer may be no, he is certainly what the original Soviet leader Lenin called a ‘useful idiot’ — referring to those in the West who ignored mass murder and chose to support the great Communist project.

That is the conclusion of the world’s most seasoned Kremlin-watchers as they assess the extraordinary antics of the Republican nominee, and the questionable background of his advisers.

Mr Trump has, by his own admission, deep business connections with Russia.

Could Donald Trump, pictured, be a Russian agent? Not likely, but he is what Lenin would have called a 'useful idiot'

His carefree ways with other people’s money — including numerous near-bankruptcies in past decades — mean that American banks shun him.

Yet his debts have grown over the past year, from £270 million to £485 million; which suggests he may have borrowed heavily.

His cash assets, meanwhile, have shrivelled. So where is the money coming from?

The short answer is Russia.

As the leading American newspaper, the Washington Post, reported: ‘Since the 1980s, Trump and his family members have made numerous trips to Moscow in search of business opportunities, and they have relied on Russian investors to buy their properties around the world.’

Trump’s son, Donald Jnr, boasted to a property industry conference in 2008: ‘Russians make up a pretty disproportionate cross-section of a lot of our assets.’

In the same speech, he said that he had visited Russia six times in the previous 18 months.

Russians helped to finance his construction projects in Toronto and, most controversially, the Trump SoHo condominium development in Manhattan.

As often seems to happen with Trump’s business ventures, investors in this project lost out; Trump had exaggerated the level of customer interest and ended up going to court.

Unusually, he settled that lawsuit, refunding most of the money in question, while continuing to deny wrongdoing.

However, court documents revealed some curious features of Trump-style business practices: mysterious infusions of cash from Russians who were ‘in favour with’ Vladimir Putin; and the involvement of two Russians with highly questionable backgrounds, including criminal convictions and other brushes with the law.

Court documents have previously revealed Trump has had 'mysterious infusions of cash from Russians in favour of Vladimir Putin' (pictured)

Trump’s partner in the Manhattan property venture was a company called Bayrock Group.

Its chairman was Tevfik Arif, a well-connected official back in the Soviet days, who was allowed by the Communist leaders to travel abroad, at a time when that was a privilege afforded only to senior KGB and Party officials.

The Bayrock executive in charge of co-operation with Trump was also from the Soviet Union.

Felix Sater had a criminal conviction for assault (using a broken margarita glass in a bar-room bust-up).

He had also worked in a stockbrokers’ firm which prosecutors later linked with four prominent mafia families and a $40 million fraud.

A disgruntled investor in an abortive Trump project in Phoenix, Arizona, claimed in a lawsuit that Mr Sater made threats against the investor which included electric shock to his testicles and amputation of a leg, followed by murder.

Mr Sater and Mr Arif deny all wrongdoing. Trump and his spokesman, meanwhile, deny that his business relationships with the men were substantial or sustained.

The fact is that questionable associations, later denied, are a regular feature of Donald Trump’s business history.

As the New York Times reported, his career has benefited from ‘a decades-long and largely successful effort to limit and deflect law enforcement investigations into his dealings with top mobsters, organised crime associates, corrupt union leaders, con artists and even a one-time drug trafficker whom Trump retained as the head of his personal helicopter service’.

But it is the Presidential candidate’s Kremlin connections which, to my mind, should attract the greatest scrutiny because they go well beyond the world of bricks and mortar.

The farcical beginning of his fascination with Russia came in 1988, when Mikhail Gorbachev, the then Soviet leader, was visiting New York.

Trump was eager for the Russian statesman to visit his Manhattan skyscraper, Trump Tower, and spread a rumour that this would be part of the official programme.

Although this was untrue, to Trump’s delight, a gleaming black limousine with outriders did stop outside the building (supposedly an impromptu halt at the request of its famous passenger).

A video shows Trump ecstatically bowing and scraping to welcome his honoured guest but the the blotchy-headed, besuited figure that emerged from the car was not the Soviet leader but an impersonator called Ronald Knapp — Trump had been victim to a practical joke.

The Republican Presidential nominee has pursued a range of business interests in Russia

Undaunted, he pursued a range of business interests in Russia, registering his name as a trademark in Moscow, and even licensing it to a distiller which launched a brand called Trump Super Premium Vodka.

In 2013, he brought the Miss Universe contest to Moscow; the first time it had taken place in Russia.

Vladimir Putin was invited and he sent a gift and a message of congratulation.

According to Aras Agalarov, a Russian property mogul who was the go-between for Trump and the Kremlin, Trump also signed a deal (on the fifth attempt) to build a Trump Tower in the Russian capital.

Like many of the billionaire’s much-talked-about projects, it remains unbuilt. It is unclear if the tycoon and the tyrant have actually met.

In 2014, Trump claimed he ‘spoke, indirectly and directly, with President Putin, who could not have been nicer’.

Yet he has also denied having ever had any personal contact with the Russian leader.

Until recently, any suggestion that the garrulous Trump would become a presidential candidate, let alone a nominee inching closer to the Oval Office, would have been dismissed as the ravings of a madman.

Yet it is entirely conceivable that Russia’s wily spymasters would see the potential value of gaining influence with an American household name; even one best known for reality TV shows like Celebrity Apprentice.

Trump, say former intelligence officials, is just the sort of ‘asset’ the Kremlin’s spy services would cultivate.

As his utterances show all too clearly, he has a colossal ego, responds with childlike eagerness to flattery, is massively overconfident in his own abilities, with an almost pathological unwillingness to admit to mistakes.

This is not the fevered or paranoid speculation of a Hollywood scriptwriter trying to imagine a sequel to the classic thriller The Manchurian Candidate (in which Soviet brainwashing is used to turn an American into a zombie-like assassin); none other than former CIA boss Michael Morell said that he had ‘no doubt’ Putin viewed Trump as an ‘unwitting agent’.

Trump’s tax returns could dispel suspicions that he is in hock to Kremlin-friendly gangsters and money-launderers but, in a scandalous breach of normal political practice, he refuses to publish them.

His flimsy, widely ridiculed excuse is that they are still being audited.

It is not simply that Trump is friendly to Russia, he is also bitterly critical of American leaders.

He is also 'bitterly cynical' of American leaders including President Barack Obama, pictured, whom he claims was 'born in Kenya'

This week he said that President Obama was a ‘founder’ of the terror group Islamic State and has also repeated the ridiculous assertion (widely shared among American conservatives) that the President was born in Kenya, not, as official records show, in Hawaii.

If true, that would mean that Obama was not a ‘natural-born citizen’ as required by the Constitution, and therefore ineligible to serve as the nation’s leader.

For years, Russia has cultivated connections in Washington in the hope of gaining political knowledge and leverage.

The Russian government and Kremlin-friendly bodies hire lobbyists, donate money to think tanks, and promote politically influential commercial ties.

Russian spies have also broken into computers related to the Democratic Party and Hillary Clinton four times, stealing a trove of documents that cast an unflattering light on the party’s internal machinations.

They have also gained access to the emails of Mrs Clinton (Trump’s rival for the White House) which were stored with amazing recklessness on a personal computer when she was Secretary of State.

Those emails can be drip-fed to the media in the run-up to polling day in November.

The duplicity and mischief they will undoubtedly reveal could capsize Mrs Clinton’s already-troubled campaign and hand the Presidency to Trump.

Another damning factor in Trump’s relations with Russia is the composition of his inner circle.

Paul Manafort, his election campaign chairman, has benefited from multi-million-dollar business deals with pro-Russian oligarchs.

He was a close adviser to Viktor Yanukovych, the disgraced Ukrainian president who was toppled in 2014.

Yanukovych, who has been dogged by a criminal record and accusations of links to organised crime, is accused in Ukraine of having been in league with Putin.

A popular uprising eventually ousted him from power and his flight to Russia two years ago was quickly followed by the Kremlin’s military onslaught on Ukraine, and the seizure of Crimea.

Mr Manafort clearly saw nothing wrong in devoting the best part of a decade to polishing the image of Yanukovych, a man reviled by his own people, and most Western countries, as a Kremlin stooge.

Even more startling is the behaviour of one of America’s top spymasters, General Michael Flynn, who now advises Donald Trump.

A former head of the Pentagon’s in-house intelligence service, the Defence Intelligence Agency, the wiry, crop-haired spy chief stunned his former colleagues by visiting Moscow in December 2015, where he sat close to Mr Putin at a dinner celebrating the work of RT, the Kremlin’s main foreign propaganda network.

Another foreign policy adviser in the Trump campaign is Carter Page, who has spent much of his career in Russia, where he served a long stint advising Russia’s national gas company, Gazprom.

Gazprom is no ordinary energy firm, but a highly politicised branch of Kremlin foreign policy, which uses the awarding of lucrative contracts to reward Russia’s allies, while penalising its foes by cutting energy supplies.

Significantly, Mr Page’s take on foreign policy chimes neatly with the Kremlin’s stance.

He justifies Russia’s invasion and occupation of Ukraine, dismissing that country’s pro-democracy revolution and pro-Western leadership.

He has decried America’s ‘often hypocritical focus on democratisation, inequality, corruption and [overseas] regime change’.

In an astonishingly offensive comparison, he even likened the Obama administration’s treatment of Russia with slavery.

But the biggest cheerleader for Russia, however, remains Donald Trump himself.

Trump has previously praised Putin for 'rebuilding Russia' but recently claimed he had 'no relationship with him'

When Mr Putin wrote an article lambasting America’s role as the world’s policeman, Trump called it a ‘masterpiece’.

In 2007, he praised Putin for ‘rebuilding Russia’.

A year later he added, in a reference to the then President: ‘He does his work well; much better than our [President George W.] Bush.’

Despite abundant evidence to the contrary, Trump denies that the Kremlin assassinates its critics. Instead, he praises the taciturn former KGB man who runs Russia for his ‘leadership’.

For his part, Mr Putin has praised the bouffant-haired buffoon, terming him a ‘colourful and talented’ person (Trump termed that compliment an ‘honour’). Later he asked rhetorically: ‘A guy calls me a genius, and I’m going to renounce [it]?’

The really worrying thing about this profoundly disturbing dossier is that it is not enough to torpedo Trump’s Presidential campaign.

It is a sign of how furious and despairing many Americans are with their political system that they discount reports of the Republican candidate’s Kremlin ties as either the product of media bias, or nothing worth worrying about.

In contrast to what American political observers call his ‘bromance’ — brotherly romance — with Mr Putin, Trump is remarkably lukewarm about America’s conventional allies.

In an interview with the New York Times, he said that on his watch, America would defend Nato members attacked by Russia only if they had ‘fulfilled their obligations’.

Americans are right to decry European countries who don’t spend enough on defence but one of the handful that genuinely do meet the Western alliance’s target, spending two per cent of GDP on defence spending, is Estonia, a Baltic state directly threatened by Russia.

If any ally deserves American support it is loyal little Estonia — a country which suffered more military casualties per head in faraway Afghanistan than any other Nato member.

Yet Newt Gingrich, the bombastic professor who many tip as a future Secretary of State in a Trump administration, dismissed Estonia as unworthy of American support in a crisis. It was, he said, merely a ‘suburb of St Petersburg’.

The message to America’s allies, one that must be echoing through the corridors of Whitehall, is chilling.

No matter how much blood and treasure you have expended in helping the United States in its wars, do not count on any support when you are in trouble.

Donald Trump, in his criticism of the U.S., echoes the anti-Americanism which the Kremlin propagates.

Key themes are that America has no moral weight in the world and no claim to global leadership.

Asked about human rights, Mr Trump said America has its own ‘mess’ to worry about: in other words, its 60-year mission to defend freedom and democracy is over.

If those fragile, ill-defended frontline states like Estonia believe they will be abandoned by their allies in a new Cold War, some of them will wonder if it is better to do a deal with Russia now — at a time and on terms of their own choosing — than have to negotiate at gunpoint, alone and friendless, some time in the not-too-distant future.

In short, Trump’s approach to the West, weakening the resolve of Nato allies, chimes exactly with Putin’s plan for destroying it.

A pro-Kremlin blogger put it like this: ‘Trump will smash America as we know it.’

Putin does not need to give Trump directions: his ‘useful idiocy’, in Lenin’s classic phrase, is enough.

What the Russian leader wants to do is to help him — notably by undermining Mrs Clinton, the only person who can keep Trump out of the White House.

Both men share a similarly nihilistic worldview. Only power matters; values count for nothing.

The difference is that Putin is a highly-skilled KGB officer, schooled in the arts of deception and recruitment.

Trump, by comparison, is the pampered child of wealthy family, who has escaped numerous well-deserved comeuppances through bluff and bombast.

If the two men ever do meet as world leaders, make no mistake: it is Vladimir Putin who will be calling the shots.

And we will all be the losers.