Counter Terrorism officers have searched the home of a British teenager who was killed in Syria last month, police said.
The officers took away material which "may be relevant to the inquiry," a police spokesman said.
Abdullah, whose uncle Omar Deghayes was held at Guantanamo Bay detention camp between 2002 and 2007, was killed in a battle in Syrian town of Kassab in April.
His brothers Jafar and Amer also traveled to Syria, their father Abubaker Deghayes said. The family says they were unaware the three brothers had left for Syria until they had gone.
Sussex Police searched the home in Saltdean, near Brighton, for two days, while Mr Deghayes and the rest of the family were made to relocate to a hotel, according to Cage, an independent advocacy organisation which says it works with communities affected by the war on terror.