Two Dartford teenagers have been arrested by detectives investigating a serious sexual assault at last year's Epsom Derby.

The pair - who are both 16 - were detained on suspicion of rape by detectives in Surrey.

It comes after a 15-year-old girl told police she was assaulted in a field close to the racecourse in June last year.

The boys have been released on police bail until Friday, January 17 while the investigation continues.