A woman who may have witnessed a teenager being sexually assaulted in Ipswich is being asked to contact police.

An 18-year-old man from Ipswich was arrested after a 15-year-old girl reported the incident which happened between 6.30pm and 7.30pm along a river tow path which passes under a railway bridge near Richmond Road on January 4.

It is believed a woman was walking along the towpath at the time and may have witnessed the assault.

She is described as a white woman, approximately 5ft 3in tall, had blonde coloured hair in a bob style and was wearing a purple coat.

The woman or anyone else with information about the incident is asked to call Pc Hannah Creasey from Ipswich CID quoting crime reference 37/10681/16.

The 18-year-old man from Ipswich has been bailed to return to Martlesham Police Investigation Centre on Thursday, March 17.