Georgie Campbell suffered a fatal accident during the Bicton International Horse Trials
Officers were called to the Phoenix Cinema in East Finchley just after 10am on Thursday following reports of criminal damage.
A total of 46 cryptosporidium cases have been confirmed in Brixham area, while more than 100 further people report symptoms
The boy is said to have fallen from the 15th floor of Jacobs House on New City Road, Plaistow, shortly before 6am on Thursday.