EXPOSED: The shadowy Islamic State cell looking to free Western jihadi brides from Kurdish refugee camps in Syria in exchange for cash raised through Facebook

Undercover reporters (bottom left placing the envelope near the service station) spent weeks communicating with a 'fixer' in Turkey before catching a 'courier' (main image and right) on camera in London last Friday picking up what he thought was a £4,500 donation to the terror group's cause. In fact, the brown envelope left at the 'dead drop' contained only a crossword puzzle book. As the Metropolitan Police began an investigation, this newspaper can reveal the sophisticated network apparently created to fund the escape of jihadi brides (top left) from camps in Syria. The camps include Al-Hol where Shamima Begum, who fled Britain aged 15 to join ISIS five years ago, was held. The Government last week launched a bid at the Supreme Court to overturn a decision to allow Begum, now 21, to leave Syria and return to the UK to challenge a decision by the Home Office to strip her of her British citizenship.