Britain's forensic science watchdog carried out a major review of the investigation into the death of Kevin "Gerbil" Carroll after a man charged with the murder - in a Glasgow supermarket car park - was cleared.
Ross Monaghan walked free in 2012 because of a lack of evidence and amid claims the police had undue influence on the forensic scientists in the case.
The review, by the UK Forensic Science Regulator, is not now expected to be published until the Carroll case is resolved, despite pressure for openness.
Yesterday, leading private forensic scientist, Allan Jamieson, said he believed the case raised issues about the independence of Scotland's labs, run by the Scottish Police Authority (SPA).
Mr Jamieson, of the Glasgow-based Forensic Institute, said: "I remain concerned that there are allegations about police influence on forensic scientists.
"Is there a possible link between these and the fact that Scotland is the only jurisdiction in the UK to have forensic laboratories operated by the police? Police may claim otherwise, but SPA labs have a single client - Police Scotland."
Forensic science in England and Wales has been privatised. Mr Jamieson has long argued this provides a more independent system.
The SPA's director of forensic services, Tom Nelson, stressed his body was not under the control of the police themselves.
He added: "This ensures a suitable degree of separation while also supporting the strong crime scene to court partnership that forensic science has with both operational policing and the wider criminal justice system in Scotland.
"We believe that the crime scene-to-court model adopted in Scotland ensures independence and impartiality for all forensic science disciplines and is preferable to the models adopted in other parts of the UK."