Syrian refugees as young as three years old are being exploited illegally as child labour by farmers and companies in Jordan, campaigners based in the Jordanian capital Amman have told the BBC.
Tamkeen, a child development charity based in Amman, claims that its investigators discovered children as young as three working alongside their parents and siblings on farms near the Dead Sea.
It claims exploitation of child labour is rife throughout Jordan, and estimates that approximately 46% of Syrian refugee boys and 14% of girls aged 14 or over are working more than 44 hours a week. The legal age in Jordan is 16.
'I work for 12 hours a day'
I spoke to one 14-year-old boy, Yassan, who works as a cleaner in a prominent business in the northern Jordanian city of Irbid for at least 12 hours a day, seven days a week.
He earns just half a Jordanian dinar an hour, the equivalent of about 50p, or less than one US dollar. This is less than half the minimum wage.
Yassan said, "I work for 12 hours a day, every day. And it's very hard work. You don't get a day off unless you ask for one and then they don't pay you.
"I get up at seven-thirty and get there for eight, but often they ask you to work later - so the earliest I get back home is at nine. During Ramadan, I had to work extra and didn't get back home until one in the morning."
I asked him if he thought he was being paid enough. "No, of course it's not good. But I couldn't find another job that could pay more.
"Of course they are taking advantage of our situation, because they don't treat Jordanians the same - they put them in a better position.
"They only use us for cleaning. We were living a better life than this in Syria but then the situation changed so we have to work."
His father Maher has been paralysed from the waist down since being tortured in Syria, and is unable to work. His mother works as a maid for a few hours a day, but she has a life-threatening blood condition.
The family - the parents and four children - owes the landlord about £1,000, an enormous sum.
'Modern slave labour'
Diala al-Amiri, the executive director of Tamkeen, said Jordanian employers were exploiting the desperation of Syrian refugee families and their children.
"Syrian refugee children are found working in restaurants, supermarkets and these kind of services, plus also the agricultural sector," she told me.
"The problem with the agricultural sector is that the kids work for really long hours, and in very bad conditions, under the sun.
"Some of them work for no money. They only work for shelter - a whole family, mother, father, with five or six kids. The biggest one is 13 years old and there are three-year-olds in the agricultural sector."
Diala al-Amiri said that farmers often kept the families of Syrian refugees separate from other farm workers, and that many were housed in tents.
"Let's say it is modern slave labour. The conditions they are living in are horrible and they are accepting them because of their vulnerability."
Of the 1.4 million Syrians living in Jordan, about 650,000 are refugees. Approximately 102,000 live in refugee camps, with the remainder living in mainly rented accommodation outside.
The last government report into child labour in 2007 said some 33,000 children were working in the Jordanian labour market. Tamkeen says that figure has almost certainly doubled since then, mainly thanks to the Syrian conflict.
Officials at the Jordanian Ministry of Labour gave the BBC details of the hundreds of companies found to be exploiting children. Last year, 213 companies were closed down.
So far this year, 353 have been closed, and a further 799 employers received fines of between 250 and 500 Jordanian dinars (£250-£500).
Nearly half of the children being exploited were Syrian refugees, the ministry confirmed.
'Revisit the law'
Dr Raghda al-Faouri, the ministry's director of policy and strategic planning, told the BBC that the government was investigating the scale of the problem and looking into the possibility of toughening up penalties for firms found in breach of the law.
"Maybe we can revisit the penalties that the Ministry of Labour is imposing. But this requires the amendment of the laws," she said.
"We have to reconsider the law and see if the measures are causing the number to increase or decrease. If there is some sort of increase we have to think about revisiting the law."
Shereen al-Taeib heads the ministry's child labour unit, which deploys 180 inspectors.
"It's not just about investigating violations or closing the company," she said.
"We need to help those children - Syrian, Jordanian or non-Jordanian."
Meanwhile Yassan's mother, Alia, expressed deep regret at having to take Yassan out of school.
"It was a very, very difficult decision because he was a very good student - one of the top students.
"He was very smart at school and I always dreamed of him finishing his education. I think of this problem every day and it saddens me every day."
For more on this story listen to Andrew Hosken's report on The World Tonight.