Inside a blue glass building overlooking the main river in Kabul sits a busy market where migrants looking for a better life begin their journey West.

It is here where Afghans seeking to cross the English Channel transfer payments to smugglers before venturing abroad, The Telegraph can disclose.

The bustling hub is home to hundreds of money exchange brokers that oversee a vast network of global transfers outside the traditional banking model.

They act as middlemen between migrants and smugglers by holding payments – made by people hoping to get to the US, UK, or other European countries through illegal means – in escrow accounts.

Only after a person successfully arrives at their destination do they instruct the broker to release the funds to the smuggler.

Worldwide, people-smuggling networks are estimated to net criminals billions of pounds. According to the European Commission, the total could be anywhere between £4 billion and £5 billion, as millions of people fleeing poverty and instability continue to leave their homes every year.