Six female migrants trapped inside a refrigerated food truck were rescued by French police after one of the women made contact with a BBC reporter, the broadcaster and French authorities said on Thursday.
When they realised the truck was going in the wrong direction, they started to panic in the cold, cramped and dark space.
One of them managed to reach a reporter with the BBC's Vietnamese service in London who helped the women to alert French police on Wednesday.
French prosecutor Laetitia Francart said the lorry driver, who was heading for Italy, was not at fault.
The women told investigators that the driver wasn’t involved, “saying that they climbed aboard the truck thinking they were going to England because of the Irish registration plates", Ms Francart said in a statement.
“After several hours on the road without a stop, they realised their mistake and alerted a journalist."
The BBC reporter said she did not know the migrants, but suggested she was contacted because of her reporting on Vietnamese migrants who suffocated in a lorry four years earlier.
The broadcaster said the woman was able to send text messages, the truck's GPS location and short videos showing the conditions inside the truck.
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The women were shown sitting in a tight space on the floor, panicking and struggling to breathe, surrounded by boxes of fruit, the BBC said.
The temperature inside the lorry was just 6°C inside, said Ms Francart, the prosecutor for Villefranche-sur-Saone.
The women were all wearing thick coats and had no health problems, she said.
French police soon tracked them down and intercepted the lorry on a motorway, the BBC said.
Ms Francart said the driver also called police after hearing noise coming from his trailer.
The six women were detained for being in France illegally before being released.
Four were given 30 days to leave the country and two were allowed to stay to seek asylum.
Ms Francart did not say how the women arrived in France.
Thousands of migrants seeking a better life in the UK try to cross from northern France every year, either by hiding in trucks or on small, unseaworthy boats across the English Channel.
Many of the migrants, who come from countries including Afghanistan, Syria and Iraq, are determined to make it across to the UK from mainland Europe because they can speak English, or because they have relatives there.
Both routes can be perilous. In 2019, 39 migrants from Vietnam who paid large sums of money to human smugglers suffocated in a lorry trailer in England.
In July, a Romanian man described by British prosecutors as part of an international human smuggling ring that made huge profits exploiting migrants was sentenced to more than 12 years in prison for the deaths.
Four other gang members were imprisoned in 2021 for terms ranging from 13 to 27 years for manslaughter.
Another 18 people were convicted in Belgium, where the Vietnamese ringleader was sentenced to 15 years in prison.
British Prime Minister Rishi Sunak’s Conservative government has taken an increasingly punitive approach to people who arrive by such unauthorised means.
The government has passed a controversial law calling for migrants who arrive on small boats to be detained and then deported permanently to their home nation or third countries.
The only third country that has agreed to take them is Rwanda, and no one has yet been sent there because that plan is being challenged in the UK courts.
In France, authorities have taken steps to try to prevent migrants entering the country from outside Europe by increasing patrols of its southern border with Italy.