Police have released an image of a man they believe to be linked to two robberies at Newham bookmakers, in which the suspect was in possession of a firearm.
The suspect entered Coral Bookmakers in Barking Road on April 7 wearing a monkey mask.
On being asked by staff to remove the mask he stated: "I've got a gun. Give me all your money."
He then produced a plastic bag containing a firearm. The second offence took place ten days later at Ladbrokes on the same road.
The main suspect is described as Asian, approximately 5ft 10 ins tall, aged in his mid-20s to early 30s, of slim build, with short dark hair and a moustache. He had possible scarring to his face and a tattoo on his neck.