It has been banned across most of Europe since 1992 because of its links to cancer.

With its old-fashioned tins and pouches that are placed between the top lip and gum, you could be forgiven for imagining the use of smokeless tobacco 'snus' (pronounced snooze) is something you would see in a working men's club rather than the Premier League's sporting theatres.

But a Sportsmail investigation has found that use of snus — which many believe gives you a mental and physical boost — has exploded among young athletes who are paid millions to play football in this country.

Jamie Vardy pictured carrying a tin of 'snus' before an England training session back in 2016

At one worried club, players found in possession of snus are fined £10,000. At another, it is two weeks' wages. Managers have told this newspaper of players taking the pouches during matches, while one well-placed source disclosed that a professional player, known to be a heavy user of snus, underwent treatment for gum cancer.

Pouches of snus cost as little as £7.99 via the internet. But there are health risks and there are also questions over whether it enhances performance. It is illegal to sell it in this country for a reason.

One academic told us certain doses stimulate alertness, power and strength. It is currently on the World Anti-Doping Agency's monitoring list.

In his 2016 autobiography, Leicester and England striker Jamie Vardy admitted to taking snus, and claimed some players were using it during matches.

WHAT SPORTSMAIL FOUND A pouch of the smokeless tobacco 'snus' was found among the debris in the Leicester City dugout at the King Power Stadium after a recent match Advertisement

Earlier this month, at Leicester's King Power Stadium, Sportsmail found snus debris in the dugout. Despite the ban on sales of snus in the UK, it is not illegal to possess or use it and a number of accounts on social media purport to be able to source the Swedish-made drug.

While there is no suggestion of wrong-doing, such accounts are followed by dozens of footballers, including Arsenal striker Pierre-Emerick Aubameyang and Newcastle's Jamaal Lascelles.

Sportsmail has been told by one well-placed source that Snus has seen a surge in popularity among young players. One manager said: 'The number of young players using it is staggering. You can see subs using it on the bench. It's disgusting and worrying.'

There are around 18 pouches in each tin, with a number of flavours such as spearmint. Names include Siberia Strong and Thunder Ultra — which Vardy appeared to be snapped with at Euro 2016. Each tea-bag style pouch gives a hit of 27.3mg of nicotine, compared to 10mg from a cigarette.

Dr Toby Mundel carried out an investigation into the benefits of taking nicotine while playing sport.

He believes it improves 'alertness, concentration, strength and power' and called for more studies into whether it gives users an unfair advantage. 'Nicotine is a stimulant,' added Dr Mundel, a lecturer at New Zealand's Massey University.

Pierre-Emerick Aubameyang follows a social media account claiming it can source the drug

'It stimulates the body and the brain. You can feel like you have been pepped up. There's an increased feeling of alertness. It helps you concentrate and is likely to have an effect on your power and strength.'

One Championship manager told Sportsmail that players are using it as an appetite suppressant without understanding the risks.

'It's absolutely rife,' he added. 'It's a disaster. It gives you a buzz and you've got players putting it in before and during games.' He added that after a recent match he saw a player insert snus on the pitch following the final whistle.

'Next time you're watching a game, look at how many players look like they have something behind their top lips. That's a tell-tale sign.' A League One manager echoed those comments and said some players were selling the drug to team-mates. 'Some of the subs will go through two or three a game,' he revealed. 'You can see the used pouches on the floor of the dugout. It's disgusting.

'I've not seen any of my players use it but, if they did, it would be a two-week-wages fine, instantly.'

Newcastle's Jamaal Lascelles is another player who follows an account which can source 'snus'

Snus is thought to have been introduced to English football by a wave of Scandinavian players. Its sale was banned in the UK in 1992 and across the European Union, except Sweden. A review is taking place at the European High Court, after an appeal by a Swedish manufacturer and a decision is expected in September/October.

John Bramhall, deputy chief executive of the PFA, said: 'It is something that we are aware of and will monitor. We will be looking to see if there is a need to educate members on the potential risks involved in using this substance.'

Colin Bland, chief executive of the Sporting Chance Clinic which deals with addiction, added: 'We are aware it's on the rise and we are aware that it's an issue.'

The FA say they warn players of the dangers of using drugs. They are monitoring WADA's stance.

A Leicester City spokesman said: 'Our players comply fully with all anti-doping regulations. We offer regular advice on a variety of topics to maintain their health and seek up-to-date research to ensure such advice is well-founded.' Newcastle and Arsenal declined to comment.