The fifth report of an inquiry into British serial killer Dr Harold Shipman has criticised the watchdog governing UK doctors.
The head of the inquiry, Dame Janet Smith, also said the General Medical Council (GMC) had still not done enough to shift their focus onto patients' needs.
"The culture within the GMC has been such that it has focused too much on being fair to doctors and not sufficiently on the need to protect patients," Ms Smith said.
"The culture of unwillingness to report doctors is still there. It must go. There can be no room today for protection of colleagues when the safety and welfare of patients are at stake," she said.
However, the report cleared the GMC of any direct blame for the crimes of Britain's most prolific serial killer - who murdered over 200 of his patients - saying the group never had enough information to lead to the discovery of the murders.
The Shipman inquiry was set up to examine the role of the GMC during the time that the doctor killed at least 215 patients, and also its conduct afterwards.
The murders shocked Britons and many wondered how a doctor who had previous convictions for forging prescriptions to feed his own drug addiction was able to continue his career and run a one-man practice.
Shipman (57) hanged himself with his bed sheets in his cell at Wakefield prison in northern England in January. He was convicted in 2000 of murdering 15 of his patients and sentenced to life in prison.
An inquiry later ruled he had killed at least 215 patients with heroin injections.