A report was made to police just after 10pm on Tuesday, September 8, after a 17-year-old girl was sexually assaulted near the Alternative Curriculum Education Centre in Lincoln Road.
Christy Stokes was arrested on Friday afternoon, September 11, in connection with the rape in Millfield.
DI Dan Pawson said: "From CCTV enquiries we believe there were two people in the area at the time of the incident who may be vital witnesses.
"I would urge anyone who was in the Millfield area of Lincoln Road around 9.30pm on Tuesday, September 8, to get in touch with us."
Stokes, of Victoria View in Smithy Fen, Cottenham, appeared at Peterborough Magistrates’ Court yesterday, September 14, where he was remanded in custody for his next appearance at Peterborough Crown Court on October 12.
Anyone with information should contact police either by using the online webchat function, or by calling 101 and quoting Operation Trundle.