The Civil Justice Council (CJC) has produced guidelines on how expert witnesses who provide evidence in legal disputes should be accredited.
But it concluded that proposals for compulsory accreditation of witnesses would be "likely to accelerate the trend" of a decline in the number of experts willing to provide evidence.
The CJC recommended that any scheme be regulated by an appropriate professional body, as it had "doubts about the ability of the accreditation schemes to act as a method of quality control" without such support.
It added: "There must be mechanisms for discipline and/or expulsion if experts fall far below the relevant professional standard."
In its guidelines, the CJC also said: "Accredited practitioners should also be required to subscribe to a common code of conduct setting out standards of professional conduct and ethics for forensic practitioners and expert witnesses."