The body was found in the boot of Ms Hossain's silver Mercedes near Tilbury railway station in Essex, the Metropolitan police confirmed in a statement.
Scotland Yard said that a post mortem would be held on the body in "due course".
Ms Hossain, 32, has been missing from her house in Manor Park, east London since Thursday April 19th.
Police have said that her disappearance was "completely out of character".
A 26-year-old man who was arrested in connection with the case has been bailed.
Ms Hossain is described as being an Asian of medium-build with long black hair which is sometimes tied in a ponytail.
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