The 34-year-old was last seen around 6pm yesterday, August 4, in Brintons Terrace, Southampton.
Officers believe he is still in the Southampton area. He may be vulnerable and confused and we would ask people call 101 immediately if they see him.
He is described as being white, of medium to heavy build, with a large black beard and short black hair.
Benjamin was last seen wearing a white Adidas t-shirt and black tracksuit bottoms with stripes on them.
If you see him or have any information about his whereabouts, please call 101 quoting the reference 44210309978.