As a photograph it barely merits a second glance, not even to Russian football fans. After all, this is the country’s national team – pictured here in Rio – that crashed ignominiously out of the 2014 World Cup in Brazil, failing to get out of the group stage.

Yet just 12 months before the 2018 World Cup kicks off in Moscow, this group of players has come back to haunt Russian football in the most dramatic way.

The Mail on Sunday has established that the entire team in the picture – indeed the entire Russian squad for Rio 2014 – is under investigation by FIFA, the sport’s governing body. And today it is asking if all 23 players were part of Russia’s vast state-sponsored doping programme.

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PROBE: (From left) Maksim Kanunnikov, Denis Glushakov, Igor Akinfeev and Aleksandr Samedov at the 2014 World Cup. They are playing for Russia in this year’s Confederations Cup

Our investigation has established that the Rio 23 and a further 11 current professional footballers are on a list of more than 1,000 ‘people of interest’, drawn up by doping investigators charged with getting to the bottom of global sport’s biggest scandal of the past decade.

It is the first time that the cloud of suspicion covering the rest of Russian sport has expanded its dark shadow over football, too, and the revelation poses further questions about Russia’s suitability to stage the tournament.

Further, it is also understood that this is the first time that an entire football team has been investigated – let alone a national team.

FIFA officials possess a dossier of detailed evidence and intelligence about the players. What action they are taking, if any, is so far unclear, although a spokesman confirmed that they are ‘still investigating the allegations.’

What is known is that four players in the picture are playing for Russia in this year’s Confederations Cup, regarded as a trial run for next year’s World Cup finals, while a fifth 2014 squad member, former Chelsea defender Yuri Zhirkov, is also at the tournament.

The Mail on Sunday has also seen explosive emails sent to the former head of the Russian drug-testing laboratory openly discussing the Government-ordered cover-up, as well as how to manipulate samples.

One email details the procedures needed to dilute a urine sample to mask high steroid levels. In another, the former lab boss Grigory Rodchenkov – who headed the doping programme and is now a whistle-blower living in the USA – fumes: ‘They’ve completely lost their last bits of conscience.’

Other sports’ governing bodies have provided breakdowns of cases and action taken. FIFA has so far declined to do so.

Russian sport has faced allegations of state-sponsored doping since Soviet times.

But in an attempt to gain international prestige, Vladimir Putin’s Kremlin has overseen a huge programme of prescribing performance-enhancing drugs to elite and emerging sports stars – and orchestrating a systematic cover-up of positive tests – both by switching ‘dirty’ for clean urine samples and by adulterating the samples themselves. It is a scandal first exposed by this newspaper in 2013.

At last year’s Olympic Games, also in Rio de Janeiro, a total of 111 Russian sportspeople were barred from competition, including almost its entire athletics team.

The ban came after an investigation by the World Anti-Doping Agency (WADA) found that Russia’s sports ministry and security agency operated a ‘state-dictated’ doping programme and covered up positive samples, while the 2014 Winter Olympics in Sochi, Russia, was also tarnished by Russian doping on an industrial scale.

Two official WADA reports published last year found at least 1,000 people were assisted by an ‘institutionalised manipulation of the doping control process in Russia’.

Our forensic examination of the evidence shows:

Hundreds of implicated Russian sports stars continue to compete at international level, with some not even coming under scrutiny from their sporting authorities, let alone being prosecuted.

At least 34 footballers are on that list, including the entire 23-man Russian squad that competed in the 2014 World Cup.

The footballers came to the attention of the anti-doping authorities because of irregularities with a number of urine samples. It is unknown if there is an innocent explanation. There are also concerns that elite footballers were protected from tests whether they were doping or not.

The global federations of some sports have been deterred from prosecuting alleged cheats for a variety of reasons, including the cost of pursuing the cases, bribery and sexual blackmail, sources say.

No official sport-by-sport breakdown of suspicious cases has been officially confirmed, but The Mail on Sunday can reveal that more than 30 sports are affected, from athletics (at least 203 Russian athletes implicated) and swimming (at least 117) to boxing (at least 7), cycling (10), weightlifting (117), skating (12), skiing (6), bobsleigh (17) and football (34).

The phrase ‘at least’ is pertinent because sources of information on some alleged Russian dopers are so sensitive that those cases have not been revealed even to the national federations, lest those sources are endangered. Other sports with cases in double figures include canoeing, biathlon, fencing, wrestling, ice hockey and rowing.

suspicion is not the same as guilt, of course. A key difficulty for FIFA and other governing bodies is that the widespread cover-up means not all the sportspeople implicated in the report can be shown to have taken performance-enhancing drugs. Some may be innocent.

However, we have established that 100 footballers’ urine samples are among a batch of around 3,500 ‘airlifted’ from Moscow to Lausanne by WADA two years ago. Today, even if the samples appear to be clean, sophisticated DNA and other testing procedures can show whether they have been tampered with or switched.

Yury Zhirkov playing for Chelsea in 2010

There are certainly grounds for suspicion. Documents seized by WADA and seen by The Mail on Sunday suggest rising panic among Russian state officials, who were fully aware of the cheating they were facilitating in the huge programme that ran at least from 2011 to 2105.

The stakes are high, and not just in sporting terms.

Two former senior Russian anti-doping officials, Vyacheslav Sinev and Nikita Kamaev, both died in mysterious circumstances within two weeks of each other in February last year. Russia knows it faces international humiliation – and perhaps sporting exile – as a result of the widescale doping.

And step by step, the world’s anti-doping police are taking notice, and in earnest. The WADA-commissioned investigative team was headed by a Canadian lawyer, Professor Richard McLaren.

They gathered evidence ranging from testimony of key figures involved, including the former head of Moscow’s main lab, Rodchenkov, to documents detailing doping schedules, spreadsheets listing samples and how they were manipulated, and countless emails and text messages.

Huge amounts of other evidence was destroyed by the Russian authorities when they realised their scheme was rumbled.

But even amid the remains, the MoS has established that there is ‘compelling evidence’ of possible anti-doping violations in around 600 cases, and ‘evidence to build on’ in hundreds more. All this was handed to global sport governing bodies in December last year, with a supplementary tranche of materials added in May.

Thousands of pages of the evidence have been placed in the public domain in anonymised form, on a dedicated ‘Evidence Disclosure Package’ (EPD) website, which the MoS has examined in detail.

Investigators want to know whether seemingly innocent samples had been artificially ‘cleaned’ while other records show irregular substances in samples, with contemporary emails questioning how the substances got there. Innocent explanations are possible.

The correspondence proves widespread doping across sports, which became so blatant that it concerned some officials who were part of the doping programme.

One email sent on Christmas Day 2013 – a few weeks before the Sochi Winter Olympics – from a colleague to the doping lab boss Rodchenkov talked about the drug-laden sample of a biathlon competitor containing three banned substances. ‘Samples like this should not make it to the laboratory,’ he wrote.

They’ve lost their last bits of conscience

Rodchenkov played a key role in providing doping products and then covering up positive tests, but even he was exasperated by the industrial-scale drug use.

One message he wrote said: ‘They’ve completely lost their last bits of conscience.’

Rodchenkov appears to implicate the Russian Government in an email in June 2014, when corresponding about a rower who had a cocktail of drugs in his system.

He asked a colleague: ‘Is rowing one of the ministerial [doping] programmes too?’

The colleague replied the next day that the drug combination was ‘well known’ in rowing, adding ‘but nevertheless, experiments like this must be authorised… and we should be notified [to expect it].’

Late in 2014, after WADA first started investigating the doping system, one of Rodchenkov’s colleagues told him in a note: ‘I hope the [sports] Ministry draw some conclusions now; we can’t continue operating in the same way [with the doping and cover-ups].’

Earlier, in August 2014, months after the Sochi Olympics had been tarnished by doped Russians getting away with cheating because Rodchenkov and the system ‘laundered’ their samples, Rodchenkov was staggered at the levels of doping products still turning up in Russian winter sport athletes.

The official translation of one email, about a bobsleigh competitor, says: ‘Why the f**k are they providing samples! It’s a bomb under the lab...

‘I suggest we screw him up to send a message to everyone else. They are taking the p*** now.’

And as late as May 2015, the manipulation was continuing, with a laboratory worker describing in precise terms to Rodchenkov how certain tainted samples needed to be artificially diluted in order to bring high steroid levels within acceptable ranges to pass tests. ‘DON’T use email for stuff like this!’ Rodchenkov blasted back in an email sent at lunchtime on May 8 that year.

‘Delete everything immediately.’

The Mail on Sunday’s revelations that Russian footballers are under investigation will come as a particular embarrassment to the president of the Russian Football Union, Vitaly Mutko, the former sports minister named in the WADA reports as playing a key role in the wider drugs scandal.

Mutko is also the man who led Russia’s successful bid to stage the 2018 World Cup. He has always denied any knowledge of, let alone involvement in, doping.

Mutko has also consistently asserted there has been no wrong-doing in Russian football.

And when The Mail on Sunday broke the story of the huge state-sponsored programme in 2013, the then-Sport Minister accused this newspaper of being anti-Russia propagandists.

Our investigation calls his protestations into question.

One source in Moscow says: ‘Mutko has kept his job at the FA only after convincing Putin that he has a key relationship with FIFA that needs to be maintained for the World Cup.’

FIFA president Gianni Infantino was pictured laughing and smiling with Putin in St Petersburg last weekend.

What happens next remains to be seen.

Even a few successful prosecutions would be an acknowledgement of an organised system that Russia will eventually be forced to admit to. But it costs around £300,000 per case and Russia is contesting most, making them prohibitively expensive for federations to pursue.

Sources also say some federations are effectively paralysed because senior officials have been drug cheats, while others have been targeted with bribery attempts.

‘There are some federation officials who have been ‘sexually compromised’, said one source, a reference to the well-worn tactic of the former KGB – but now it is the Russians who find themselves targeted and who, across a range of sports at least, quite hopelessly exposed. And it is the turn of football fans to ask some hard questions of the Russian stars, however ineptly they perform.