Niaz Ibrahimi was only 13 when he was bundled into a lorry by his family to flee Afghanistan and the death threats of the Taleban.

Leaving behind his tearful family, Niaz and up to 15 other teenage boys found standing room between cables and pipes. Told not to talk by the violent lorry drivers, they then travelled for thousands of miles across continents with little food and water.

“After about three or four days I thought I was going to die,” Niaz recalled. “It was hot, I had a headache and I felt sick and had eaten nothing.”

Finally the doors were opened. Unknown to the boys, who could speak only Pashto, and had been only to Koranic school in Afghanistan, they were in France.

“We saw lots of green and motorways and jungles. There were cars swishing past so fast. I’d never seen anything like that,” he said. Avoiding the kicks of a driver, the boys attempted to run but were captured by police and taken to jail.

What happened next is hazy in Niaz’s mind. Some of the boys were taken to a house where a group of men, after asking for money they did not have, took them to another lorry and their journey continued. “It was a long time and there was no space to sit,” Niaz said. “Our legs hurt. I don’t know if we came by train or boat. Then much later the driver found us and called the police. They told us we were in Swindon. I had never heard of the UK before.”

The memories of the traumatic journey, during which he lost his family’s phone number in Afghanistan, remain with Niaz, now 16.

But he has decided now to tell his tale to The Times to highlight the trauma that was to follow once he had arrived and was cast into the British immigration system, which was described this week as caring more about “protecting borders than about protecting children”.

The UK Border Agency is initially responsible for the thousands of unaccompanied children smuggled into Britain each year. They then farm them out to local authorities. The Refugee Council said this week, however, that each year councils were given little warning of how many children to expect, despite a Border Agency pledge to designate a group of local authorities who would receive set numbers of childen and be given specialist training.

The Refugee Council said that immigration officers and border officials were given little training in how to deal with vulnerable children.

A Home Affairs Select Committee report last week also criticised the training provided to immigration judges while local authorities complain about how difficult it is to get the Home Office to meet all funding claims. Niaz became a victim of this inconsistent and underfunded system.

After initially being told that he would be placed with an Afghani family, Niaz ended up with an Indian family and was told it “was all the same to them”. He said: “At school it was hard at first. There were racist people who would push me. Slowly, slowly I made friends by talking nicely to people and not fighting.”

School was not the only problem, however. For three years Niaz was shunted from town to town, school to school, and family to family.

It was only when he came to the attention of Community Foster Care (CFC), a charity in Gloucestershire, that his fortunes changedand he was placed with a foster family from its network.Now he is thriving and works as an interpreter with the CFC. Recently he won an award for his voluntary work.

Despite being unable to contact his family, Niaz now feels that Britain is his home. “Life in Afghanistan was harder than in the UK. Now I can go to school, play football and cricket and have slowly made friends. I want to study engineering if they let me stay when I turn 17,” he said.

It helps Niaz that his foster family also cares for Norma, an Iraqi teenager, who had perhaps an even more harrowing journey to Britain. Norma, 14, was found in December strapped to the underside of a lorry by a belt between the axles and covered in diesel fuel.

Niaz has advice for other families considering sending their children to what they hope will be a better life: “I would tell them not to do it. Even if they are trying to kill you at home, you might die in the lorry.”