The cases of 16 children who were left in another country by their parents to be married off or ‘de-westernised’ have been reported to a national hotline in the first five months of this year.

However, the true number is likely to be far higher, the AD reported on Thursday at the start of a nationwide campaign to raise awareness of the issue.

In 2015, when the LKHA was launched, 23 children were reported as to having been left behind. In 2017 there were 30 and this year the total is set to be higher, the AD said.

In around half the reported cases, officials manage to have the child brought back to the Netherlands, but they are often traumatised by the experience.

‘The number of reports always rises after the summer holidays,’ spokeswoman Diny Flierman told the paper. ‘Children are often fooled into thinking they are going on holiday but when the rest of the family returns to the Netherlands, they are left behind.’

Rough estimates quoted by the AD put the real total at between 180 and 800.

Teachers are being urged to report it if they feel children are frightened to go on holiday or if they fail to come back. ‘But it is important they do not raise the issue with parents, because that could put the child in danger,’ Flierman said.