Police are investigating a sex assault on a woman in a Brighton park.

The 37-year-old was walking along Lewes Road towards Moulsecoomb at about 10.30pm on Friday when she was offered a lift by a man in a dark 4x4 car.

He drove her to Stanmer Park where he told her to get out and led her away from the car.

She agreed but claims she was sexually assaulted after following him.

The man reportedly got back in his car and drove away.

Sussex Police believe a group of men in their mid-20s walked past the man and woman as they stood outside the car.

They are urging the group, or anyone else who saw anything suspicious, to contact them.

Anyone with information is asked to call DC Katy Hartley at Brighton and Hove CID on 0845 6070999 quoting reference 2085 of August 28 or Crimestoppers anonymously on 0800 555111.