Border Force officers searched a trailer at Immingham Docks which had arrived from the Netherlands on Thursday night.
They found 8,960,000 cigarettes inside 20 wooden pallets.
If undetected, the Border Force estimated the haul would have cost the Treasury Â£2.5m in unpaid duty and VAT.

Two quickfire Omar Bogle goals just before half-time gave Grimsby control.
Forest Green fought back after the break and Keanu Marsh-Brown's superb goal reduced their deficit after Jon Parkin had missed from six yards.
But Grimsby - playing in the play-offs for a fourth consecutive year - struck a late third through Nathan Arnold.
Paul Hurst's side, who lost to Bristol Rovers on penalties in last year's final, had seen Arnold's long-range strike tipped onto the post shortly before taking the lead at Wembley.
Bogle then glanced in Jon Nolan's free-kick via Rovers' Darren Carter's back to open the scoring, before volleying in from six yards on the rebound to double Grimsby's lead just one minute later.
Forest Green introduced substitute Parkin at half-time and the 34-year-old former Preston striker's presence changed the game.
Parkin could only hit the side netting from Forest Green's best chance, inside the six-yard box, before Marsh-Brown's sweet, dipping strike gave them hope.
But Forest Green, who had finished nine points above Grimsby in the league table, could not find an equaliser despite a spirited fightback.
Rovers, who sacked manager Ady Pennock one week before the start of their semi-final against Dover to "boost their chances in the play-offs", had set a fifth-tier record of nine consecutive wins to start the season, before being beaten to the league title by Cheltenham Town.
Having finished in their highest-ever league position in second, they were led at Wembley by caretaker boss Scott Bartlett, while next season's manager, Mark Cooper, offered guidance from the dugout.
But the Nailsworth club - who had hoped to make their home town the smallest settlement to ever host a Football League club - saw their promotion hopes dashed in the play-offs for the second year running.
Arnold, who had a low shot saved with 15 minutes to play, completed the win in stoppage time, tucking in on the rebound to end Forest Green's hopes of a late twist.
The promoted Mariners return to Wembley on 22 May for the FA Trophy final against FC Halifax.
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Grimsby boss Paul Hurst told BBC Radio Humberside: "I'm quite relaxed. I feel quite calm. It's a fantastic achievement.
"Those players, rightly so, will go down in the club's history.
"It's far from job done yet - we want to make sure that we're a Football League club for a long time to come and, if possible, see if we can move the club even further forward."
Forest Green Rovers striker Jon Parkin told BBC Radio Gloucestershire: "It was just a mad five minutes in the first half that put us on the back foot.
"In the second half, we've come out and had a real go. (We had) a couple of chances, should have scored and it's a totally different game.
"But that's the difference - they took their chances, we didn't."

Guineans are expected to celebrate the landmark with concerts and fireworks.
Sierra Leone was declared free of Ebola in November, but new cases have been discovered in Liberia, which had been declared Ebola-free in September.
The disease killed more than 2,500 people in Guinea, and a further 9,000 in Sierra Leone and Liberia.
Even though there has not been any new cases of Ebola in 42 days, local health workers in Guinea and the World Health Organisation warned that people should still be very careful.
"The coming months will be absolutely critical," said Dr Bruce Aylward from the World Health Organisation's Ebola response team.
"This is the period when the countries need to be sure that they are fully prepared to prevent, detect and respond to any new cases."
Almost nine million cigarettes hidden inside packages labelled as containing wooden flooring have been seized at a port on the River Humber.
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Grimsby Town returned to the Football League after a six-year absence with victory over Forest Green Rovers in the National League promotion final.
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The World Health Organisation has declared Guinea, in West Africa, free of Ebola, two years after the outbreak of the virus began there.