Officers from Hampshire Constabulary have sealed off a property in Winchester.
Police have cordoned off Windsor House in Lawn Street.
A large police presence is visible in the area and officers have been seen carrying out searches
Concerned neighbours say that Police turned up in the early hours of Tuesday morning at around 2am.
An officer remains on scene guard at the property.
A Hampshire Constabulary spokesman said Officers have cordoned off an area of the garden outside Windsor House
An attack took place in the early hours of Tuesday, May 14.
An investigation is in its initial stages the woman is being supported by specially trained officers.”
No arrests have been made at this time.
Anyone with information should call police on 101, quoting the crime reference number 44190165181.