Plans to overhaul the coroners' system will fail to stop another serial killer like Harold Shipman, says a pathologist who exhumed a dozen of the GP's victims.

In a critical article in a leading medical journal, Dr John Rutherford accused David Blunkett, the Home Secretary, of "tinkering" with the system rather than introducing the sweeping reforms which are needed. The Government's failure to replace coroners with properly funded forensic pathologists will "almost guarantee that episodes of foul play will go undetected", he warns.

Dr Rutherford, a forensic pathologist, played a central role in the Greater Manchester police investigation into the Shipman deaths, digging up and performing autopsies on 12 of his victims.

Shipman is serving 15 life sentences after his conviction in January 2000 for killing 15 of his patients with diamorphine. Police are convinced he murdered at least 26, and the subsequent inquiry estimated that he probably killed at least 215 people.

The Home Secretary is expected to support calls by a series of inquiries into the Shipman case by overhauling the death certificates system which allowed him to cover up his murders and setting up a new system of "medical assessors" to oversee the use of death certificates by doctors.

But Dr Rutherford has launched a scathing attack in the Journal of the Royal Society of Medicine, claiming that the expected reforms are inadequate and Britain should adopt the US system where all deaths are reported to a full-time medical examiner, who decides in each case whether it should be investigated by a trained pathologist based at a high-tech forensic centre.