A third man has been arrested on suspicion of attempted murder and serious sexual assault after a “horrific” attack left a woman in a life-threatening condition.
The victim, who is in her 50s, was discovered near a children's play park off Cedar Road, Leicester, at 4.45am on 3 August.
A 16-year-old boy and 56-year-old man have also been arrested in connection with the crime, however the older man has since been bailed.
Crime scene investigators conducted a detailed examination of the scene, which had been cordoned off, and CCTV footage was viewed as part of the inquiry.
The force said police inquiries are continuing and the victim remains in a stable condition in hospital.
Speaking on Thursday before the arrest, Detective Inspector Mark Sinski, from East Midlands Special Operations Unit Major Crime, said: “Our thorough and detailed investigation into what happened during the early hours of 3 August is continuing and there are still a number of lines of inquiry that we are following.
“Today, officers have been deployed to the area around the park to ensure that no stone remains unturned in our investigation.
“This has included searching drains in Cedar Road and the surrounding area to see whether anything can be recovered that will help us in catching the person responsible for this brutal attack.”
He added: “We owe it to both the victim and the people of Leicester, Leicestershire and Rutland to find the person responsible for this horrendous crime.”
Detectives examined drains while plants were stripped back to allow officers to complete a comprehensive search of the area on Thursday.
Hundreds of leaflets were also handed out in and around Cedar Road calling for the public to help with an investigation into the assault.