A young Afghan boy saved himself and the lives of 14 adults by texting for help from inside a refrigerated truck in which they were being smuggled to Britain, a charity worker who helped him said on Friday.

Ahmed, who is aged six or seven, used a mobile phone given to him by a British aid worker in a French migrant camp to warn her that they were running out of oxygen.

Volunteer Inca Sorrell was attending a conference in New York when she received his texts and contacted a colleague in Britain, Tanya Freedman, who alerted police.

Officers traced the phone and stopped the truck, taking all those inside into the care of immigration authorities.

"It's an extraordinary story. It's a global network of people who came together to save lives, led by this young boy," Freedman, who works at British charity Help Refugees, told AFP.