Thames Valley Police is investigating a report of a rape on a man in Greenleys last night.
The incident is believed to have happened at around midnight, on the Redway at the rear of Lamberts Croft near to an overbridge.
A man in his twenties was assaulted by a group of men and raped.
Detective Inspector Nick Glister, of Milton Keynes CID, said: “Our investigation is at a very early stage and the man is being looked after by specially trained officers. At this time he has not yet been formally interviewed by officers.
“We currently believe that between four and six men were involved, but we are unable to give any further details until we have completed our initial enquiries. However, I would like to reassure people that we are treating this report very seriously and a team of detectives is working to gather evidence. Cordons are in place to allow access to investigators.
“We are keen to hear from anyone who witnessed the incident or any suspicious activity in the area, or has any other information which may assist us with our investigation.
“We appreciate that this incident is likely to cause concern in the community and we ask anyone with any concerns to contact their neighbourhood team via 101. We also take this opportunity to remind people to remain vigilant when out and about and report any suspicious activity immediately.”
Any witnesses can call police on 101