Kadiza Sultana was 16 years old when she and two friends from school secretly fled home to join the Islamic State.
The girls' parents say haven't heard from them since mid-December, when they were told that they had been married off to older men by the terrorist group.
The unnamed 16-year-old London schoolgirl may may have been "intimately involved" in details of one of the teenagers who made the trip to Syria earlier in the year.
A note describing how to pray, seen by VICE News, formed part of cache of documents handed to police as evidence that three UK girls had been groomed by IS before traveling to Syria in February.
VICE News gained exclusive access to the families of Shamima, Amira, and Kadiza, the three schoolgirls who left London to join the Islamic State in Syria. This is their untold story.
Top officers apologized for police handling of the case after VICE News revealed investigators had been in contact with the girls about a friend who had left for Syria, but did not inform their parents.
Police and school failed to tell the girls' parents that officers spoke to the teenagers twice at their school before their disappearance.
This weekend, one of George Osborne's senior advisors was filmed smoking crack.