An investigation was launched after a man in his 20s reported he had been attacked by another man in Morden Hall Park shortly before 7pm on Monday, 25 July.
The suspect is described as a white man, aged around 50, about 6ft tall, of slim build with a short grey beard. He was wearing black thin rimmed glasses, a blue top, blue shorts and a luminous yellow cap.
The man is being supported by specially trained officers.
Detective Constable Hannah Saunders, from the South West Basic Command Unit, leads the investigation and said:“We have released an e-fit image of the man we want to speak to. Give the detailed description provided I hope someone may recognise him – if you do, please get in contact.”
Anyone with information that could assist police is asked to call 101 or tweet @MetCC and quote CAD 5617/26Jul. You can also speak to the independent charity Crimestoppers anonymously on 0800 555 111 .