The mother of murdered teenager Stephen Lawrence fears the probe to find the rest of her son's killers will "wind down" after the lead investigator retires this year.
Doreen Lawrence told the Daily Mirror she was "furious" that Detective Chief Inspector Clive Driscoll, the senior officer in the case for a number of years, would have to hand over his role.
She has requested a meeting with Metropolitan Police Commissioner Sir Bernard Hogan-Howe to discuss her concerns over the future of the investigation.
Baroness Lawrence said: "I'm absolutely furious Clive is being taken off the investigation.
"It seems the clearest sign yet that the Met is planning on winding down the investigation and that is wrong.
"He is the first officer I have trusted and the only one to have delivered in the investigation."
Mr Driscoll, who in 2012 helped secure the convictions of two men for the attack, told the newspaper: " The decision has been made above me and I will always help Stephen's family and friends if I can."
A spokesman for Scotland Yard said Mr Driscoll was among a number of detectives on the case who had served for more than 30 years and had reached "natural retirement ".
Mr Lawrence, an 18-year-old aspiring architect, was stabbed to death by a group of up to six white youths in an unprovoked racist attack as he waited at a bus stop in Well Hall Road, Eltham, south-east London, with a friend on April 22 1993.
In January 2012 Gary Dobson and David Norris were found guilty of being involved in the attack and sentenced to life imprisonment, after a forensic review of the case found significant new scientific evidence on clothing seized from their homes following the murder.
Police continue to hunt for the rest of the gang.
A spokesman for Scotland Yard said: "DCI Driscoll is due to retire later this year.
"The MPS has a dedicated team of detectives that continues to investigate the murder of Stephen Lawrence to bring any remaining offenders to justice.
"A number of these detectives have exceeded their 30 years police service and are due for natural retirement. As part of our succession planning and to provide resilience, new officers will join the team in early 2014 and replace those due for retirement."