Children are missing in the overcrowded camps in Calais and other parts of France as migrants make the perilous crossing, with a third of the children reported missing.
A total of 3,972 children, including 474 children under the age of 10, have been reported missing in recent months, according to figures from the French authorities.
The authorities have warned of an “urgent need” to rescue the children, and have set up a hotline to call for help.
Many of the migrants have fled to the nearby UK to escape the crisis, but many are still stuck in the Calais camps, where they are unable to leave.
In recent months the numbers of migrants arriving in France has rocketed.
More than 12,000 people arrived in France in January alone, up from 8,000 in the same month a year earlier.
The number of migrants and refugees arriving in Britain rose by more than 300% to 6,400 last year.
In the latest figures, 1,731 children under 12 were reported missing from the camps.
Many are now in temporary accommodation, including a five-year-old boy who has been living in a tent in the centre of the French port city.
His mother, a teacher, said she had received a phone call from him just before the arrival of the police.
The boy’s family was told to stay put, she said.
The family was able to secure temporary accommodation in a hostel in nearby Montpellier, but said they were not allowed to leave until the police arrived.
A week after the arrival on Thursday of the first police officer, Mr Alcock said the family had found another tent on the side of the road.
He said the police had found no children there, adding that they had to take their child to a doctor’s appointment in France every three days.
The father of one of the boy’s friends said he was scared because his friend’s parents had been unable to find him.
The parents of two of the other children have been in the camp for about three weeks.
One of the boys was at school when the police were finally able to rescue him on Thursday, he said.
He was found in the tent and is now at a hospital, his mother said.
Another child, aged six, who is also from the camp, is also being looked after by a carer, Mr Raffaud said.