Anyone with a scientific background and "a brass neck" could portray themselves in court as a scientific expert, a senior judge has said.
Lord Justice Leveson has called for the "reliability and use of expert evidence in law" to be improved.
The Sentencing Council for England and Wales chairman made his comments in a speech to the Forensic Science Society.
He also warned that a jury might simply defer to a convincing expert when considering a case.
He also said that stricter accreditation of the UK's forensic scientists was "hugely desirable".
Lord Justice Leveson said: "In the United Kingdom there has traditionally been no system of accreditation or regulation of forensic scientists.
"The dangers of this lacuna are obvious. Theoretically, anyone with any sort of scientific background and sufficient personal confidence, perhaps less politely described as brass neck, or who was sufficiently misguided, could set themselves up as a forensic science expert and produce evidence that, at best, is unhelpful and, at worst, positively misleading.
"Nobody would necessarily be the wiser."
In his speech, he also said: "Effective control over, and management of, expert evidence by the judge is of paramount importance in the context of any scheme relating to admissibility and identification of issues."
And Lord Justice Leveson also warned that it was possible that "a jury may simply defer to the knowledge and opinion expressed by a convincing expert when considering how to resolve the issues in dispute".
"Expertise has proliferated in ways we ought to be careful about," he said.
"Parties look increasingly towards experts as a panacea, a fix all, a universal solution to the evidence - or lack of evidence - in the case."
He said there had been a failure "to propose a consistent approach towards the admissibility" of expert evidence.
It may be desirable to ensure that expert evidence in pioneering areas of medical or scientific development "should not be admitted until the developing area is sufficiently organised or recognised to be accepted as a reliable body of knowledge and experience," he added.
The Law Commission, which reviews and recommends reform of the law in England and Wales, has written a report which calls for a new basis for screening expert evidence.
This would ensure, it said, that only sufficiently reliable evidence will be considered in court.
But Lord Justice Leveson has called for even more to be done, suggesting the regulation or accreditation of forensic scientists.
This could perhaps be achieved by a system of peer review, he added.