The investigation continues after a 16-year-old girl was the victim of a serious sexual assault.

It happened at around 11.20pm in Thetford on Thursday, June 3, in a grassed area off Canterbury Way, close to a path which runs along the river in the direction of London Road.

The teen victim was approached by an unknown man before being sexually assaulted.

Thetford & Brandon Times: An area of Thetford has been sealed off by police after a 16-year-old girl was sexually assaulted.An area of Thetford has been sealed off by police after a 16-year-old girl was sexually assaulted. (Image: Sarah Hussain)

The man is described as black, of slim build, approximately 6ft, aged in his late teens or early 20s, with black hair. His hair is described as short on the sides and long on top, with no facial hair.

He is believed to have been wearing black jogging bottoms with a black top and black t-shirt underneath at the time.

Thetford & Brandon Times: An area of Thetford has been sealed off by police after a 16-year-old girl was sexually assaulted.An area of Thetford has been sealed off by police after a 16-year-old girl was sexually assaulted. (Image: Sarah Hussain)

Det Insp Richard Weller said: "We are keen to speak with anyone who may have seen a man matching the description in the area stated, or the local vicinity, including Bridge Street at around 11pm.

"We know there were quite a few people out in this area at that time who may have seen this man and we urge you to come forward.

Thetford & Brandon Times: An area of Thetford has been sealed off by police after a 16-year-old girl was sexually assaulted.An area of Thetford has been sealed off by police after a 16-year-old girl was sexually assaulted. (Image: Sarah Hussain)

"We know this type of incident is likely to cause concern within the local community, and as a result officers continue to conduct reassurance patrols in the area.

"We encourage members of the public to speak with local officers about any concerns they may have. Police continue to support the victim and her family."

Thetford & Brandon Times: An area of Thetford has been sealed off by police after a 16-year-old girl was sexually assaulted.An area of Thetford has been sealed off by police after a 16-year-old girl was sexually assaulted. (Image: Sarah Hussain)

Police are appealing for anyone who may have witnessed the incident, or has any information concerning it, to come forward. They are encouraged to contact Swaffham CID on 101 quoting Operation Hemisphere.

Alternatively contact Crimestoppers anonymously on 0800 555 111.