A floating barrage of buoys was stretched across a river near Etaples and Le Touquet in northern France.
There are fears smugglers are using waterways to launch boats after a police crackdown on the beaches.
But just yards away, on the Channel side of the blockade, is a runway into the water and a car park.
The site is significant because many smugglers will drop dozens of migrants off by vehicle moments before they attempt to launch a dinghy destined for the UK.
Alp Mehmet, chairman of Migration Watch, told the Daily Express: "Is this an indication of how the French regard illegal migration? It's time they took it seriously and put the millions we give them to better use.
"They could start by stopping more boats from setting off illegally from France. They should also accept back those who make it into British waters. They might then find fewer enter France with the intention of making their way to the UK."
The discovery heaps pressure on French authorities as it emerged a record number of migrants have crossed the Channel at the start of this year. So far 11 people have died trying to reach our shores in 2024, according to migrant charity Care4Calais -including a seven year-old girl killed last week when a flimsy inflatable collapsed in the River Aa.
Denne historien er fra March 08, 2024-utgaven av Daily Express.
Start din 7-dagers gratis prøveperiode på Magzter GOLD for å få tilgang til tusenvis av utvalgte premiumhistorier og 9000+ magasiner og aviser.
Allerede abonnent ? Logg på
Denne historien er fra March 08, 2024-utgaven av Daily Express.
Start din 7-dagers gratis prøveperiode på Magzter GOLD for å få tilgang til tusenvis av utvalgte premiumhistorier og 9000+ magasiner og aviser.
Allerede abonnent? Logg på
'I want the chance to prove myself again'
PEP GUARDIOLA feels the need to prove himself all over again-despite his glittering successes at Manchester City.
SEAN HAILS BRAVE CALL
SEAN DYCHE says Everton made a \"brave decision\" to reject Manchester United's £50million offer for Jarrad Branthwaite.
Howe looks to end Toon striking issue
EDDIE HOWE is banking on the competition between Alexander Isak and fit-again Callum Wilson to spark a faltering attack.
Iraola won't play it by the book
ANDONI IRAOLA admits Bournemouth will miss Antoine Semenyo but is happy to accept yellow cards as the price for the club's style of play.
McKenna refuses to rest on laurels and asks for more
KIERAN MCKENNA has warned Ipswich they must build on their improving Premier League form.
Davies sends Blades to top of pack
TOM DAVIES came off the bench to score a late winner as Sheffield United went top.
STAYING AT RED BULL IS TARGET FOR MAX LEGACY
Champion insists he does not need to win elsewhere
How Pope managed to get out of a Stew
OLLIE POPE revealed a heart-to-heart with his mentor Alec Stewart helped pave the way for his timely return to form against New Zealand.
Former intern fights boss for half his £1m company
AN antiques dealer to the stars is locked in a bitter court fight with a former intern who says she has a right to half of his £1million firm.
Highgrrrove's not too ruff for us...
MISSY the English cocker spaniel looks excited to be meeting a King Charles, but Percy the white bichon cross appears to have realised her mistake...