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.
As the man was walking through the park, he realised he was being followed. He was pushed to the ground and raped in a wooded area before managing to escape.
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 .