A girl of 12 has been raped in woodland at a play park, police said.
Thames Valley Police said she had been on her own when a man pulled her to the woodland area, attacked her, and then fled.
The incident was reported to police yesterday and a scene watch is currently in place to allow a forensic examination, a force spokeswoman said.
The girl was attacked around March 23 at about 3pm at the end of the play area in Harrowden, Bradville, in Milton Keynes.
The victim is described as a white girl, aged 12, 5ft, of slim build, with long shoulder length mid-brown hair. She was wearing glasses.
Police said the offender is described as a white man, aged around 45 and of skinny build.
Investigating officer Detective Chief Inspector Justin Fletcher said: "We would urge anyone who saw the victim or a man answering this description in the area around that time to contact us as a matter of urgency.
"We take all allegations of a sexual nature very seriously and understand how difficult it can be for victims to come forward.
"While this was a very traumatic incident for the victim, it is also very rare.
"We would like to reassure the community that we are investigating the matter fully and patrols will be in the area to provide extra reassurance."
Police have appealed for any witnesses to the incident or anyone who has information as to the identity of the suspect to call the Thames Valley Police non-emergency number 101 quoting URN 589 05/05/13.
Alternatively, anyone with any information can contact Crimestoppers anonymously on 0800 555 111 or online at crimestoppers-uk.org.