It happened in the early hours of the morning of Thursday 15 August in the New Walk area of York between Skeldergate Bridge and Blue Bridge.
The area was closed off and a scene guard was put in place to allow investigators to examine the scene.
A 19-year-old man was arrested on suspicion of rape on 15 August and taken into police custody where he remains for questioning.
Extensive enquiries are continuing into the incident and the victim is receiving support from specially trained officers.
If you have any information or saw any suspicious activity between 2am and 4.15am in the riverside area known as New Walk, Clifford’s Tower and Tower Street please contact the police.
Please call 101 and pass information for incident number 12240147701.
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