Three British nationals have been arrested in France on suspicion of attempting to fly four Albanian migrants to the UK.
French police officers detained the men, one of whom is said to be a pilot, as they were about to depart from Marck airport near Calais with their human cargo.
Their plane was preparing for take-off when the arrests were made.
The migrants – one Albanian man, two women and a child – were also detained at the scene.
One man and one woman were taken to an immigrant reception centre after their arrests, while the other woman and her child disappeared after being taken to a nearby hospital to be checked over.
Speaking with the La Voix du Nord newspaper, Philippe Sabatier, the deputy prosecutor for the north Channel area, said the case appeared to be the first of its kind.
He said that while French authorities are used to seeing people smugglers use trucks and boats to sneak migrants across the Channel, this was the first time traffickers had been caught using a plane.
French police are working with their counterparts in the UK to establish the background of pilot, Sabatier added.
The three smugglers face charges of “helping undocumented foreigners as part of an organised group”, the prosecutor said.
Responding to the arrests, Conservative MP for Dover Charlie Elphicke is quoted by Kent Online as saying: “Yet again we see that ruthless people traffickers will stop at nothing to break migrants into Britain.
“We’ve cracked down on smuggling through lorries, dinghies and small boats. Now they are using light aircraft.
“We cannot allow this latest extreme tactic to take off. We must smash the trafficking gangs and end their evil trade of modern slavery.”
The aircraft the men were planning to use would have taken less than an hour to reach an airport in the south of England.
While all planes that travel from France to the UK must land at an airfield with customs controls, some sites only carry out cursory checks on people travelling on small aircraft, meaning the men might have stood a good chance of smuggling the migrants into Britain.
Scores of UK-bound migrants have returned to the area around Calais in recent months following the closure of the notorious Jungle camp in October last year.
Earlier this month, a report accused the UK government of leaving vulnerable lone migrant children at the mercy of ruthless people smugglers in the Calais region.
In a forward to the report, based on an inquiry led by Baroness Butler-Sloss and former Labour MP Fiona Mactaggart, its authors wrote: “These children, who are not yet here, are facing daily risks and dangers which simply would not be tolerated if they were visible to us all.”