Cold case detectives investigating the murder of a six-year-old more than 20 years ago saying they are "closing in" on those responsible.
Rikki Neave was last seen leaving his home on the Welland estate in Peterborough to go to school on November 28 1994.
His naked body was found in nearby woodland the following day. A post-mortem found he had been strangled.
His mother Ruth Neave, now 45, was charged with murder but later found not guilty by a jury. She pleaded guilty to child neglect and cruelty and was sentenced to seven years in prison.
Cambridgeshire Police launched a fresh investigation earlier this year following pressure from Ms Neave.
Marking the 21st anniversary of Rikki's disappearance on Friday, Detective Chief Inspector Richard Wall said there had been "significant progress" in identifying who killed him.
He added: "We have had an overwhelming response from the public and have built a strong timeline of Rikki's last movements.
"Even 21 years on people still remember clearly the events leading up to Rikki's death and I would urge people to continue to come to us with any information they have.
"We are confident that we are closing in on those responsible for Rikki's death and it is only a matter of time before we have that vital breakthrough that leads us to them."
Mr Wall said the team was working with experts to re-examine original forensic samples with new technology.
This weekend detectives will be on the Welland Estate continuing their inquiries.
He added: "At the time of Rikki's death we know that drug use was commonplace on the estate and are keen to hear from any professionals who may have been helping people and given information about the murder."
An artist's impression of two young men seen around the crime scene at the time of Rikki's death were recently released.
A £10,000 reward is being offered to anyone who provides information which leads to the arrest and conviction of those responsible to Crimestoppers.
Anyone with information should contact police on 01480 425882, email firstname.lastname@example.org or call Crimestoppers on 0800 555111.