Police are investigating a sexual assault that took place in Oxhey Park at 6.15pm on Monday, when a boy was said to have grabbed a woman's bottom. 

The boy was described as black, aged between 14 and 17-years-old, about 5ft 7ins tall, with a slim build and cropped hair. He was said to be wearing a maroon polo shirt and a navy baseball hat. 

If you believe you witnessed this offence, or may know who was responsible, you can telephone Detective Sergeant Matthew Waylett via the Herts Police non-emergency number, 101 quoting crime reference C1/14/3601.