At around 5.15pm on Sunday, 31 May, a man exposed himself to a girl on Lovegrove Walk, E14.
The man did not speak to the girl nor did he make any physical contact with her.
Following the incident, the man walked off in the direction of Preston Road, E14
The girl, aged under 13, told her mother what had happened who then called police.
The man is described as white and between 20 and 30 years of age.
PC Daniel Olney, investigating, said: “I am keen to identify the man in the image as part of our ongoing investigation. This was understandably an upsetting incident for the young girl and her family. We are keen to identify the person responsible as soon as possible.”
Anyone with information is asked to call police on 101 quoting reference Cad 6066/31May or Crimestoppers anonymously on 0800 555 111.