In April 1995, a 13-year-old girl was found by the police on Abercrombie Way, Harlow.
She described that she had been with her friend and speaking with a group of unknown men who were in a car close to the BP garage on Southern Way.
She was then sexually assaulted and raped by the suspects in the car.
Now officers have arrested a 57-year-old man from Harlow on connection with this investigation.
Det Chief Insp Greg Wood, of the Essex Serious Crime Directorate, said: “Today’s arrest is due to the ongoing tenacious work by our Cold Case investigation team.
“This is a significant investigative development – but we know there were other men in the car when the young victim was sexually assaulted.
“They know what happened that night.
“I would encourage them to contact the police so they have their opportunity to tell us what happened.
“We believe the answers about this assault are still in the community in Harlow, so if you have information you believe may be useful to the detectives in this case please come forward.
“No detail is too small when we are working to make sure the victim in this case sees justice done.”
Anyone with any information should contact police quoting reference 42/133093/24.