A cold case team are carrying out a review of the Rikki Neave murder case.
Cambridgeshire Police have stated that a team of detectives is overlooking the evidence.
Six-year-old Rikki , who had family connections to March, was found strangled and dumped in a ditch 500 yards from his home in Redmile Walk, in Welland, Peterborough, on November 28, 1994.
His mother Ruth has been calling for police to look at a number of issues surrounding the original investigation.
A police spokesman said: “We are carrying out a comprehensive review of the entire case to establish if there are grounds for the investigation to be reopened.
“The dedicated cold case review team consists of two to three people.
“Additional forensic work means a review using modern technical standards.”
Detectives will be go through 700 statements, 456 documents and 902 messages linked to Rikki’s death.
In 1996 Mrs Neave was jailed for seven years for neglect after admitting “appalling ill-treatment” of the youngster but was unanimously cleared of murder by a jury.
In August last year Cambridgeshire police reviewed the case before deciding there was not enough evidence for a fresh investigation.