Between 15 percent and 20 percent of qualifications presented to employers these days were fraudulent, credentials verification company Kroll MIE said on Monday.
The problem of fake qualifications was on the increase and had reached "near-epidemic proportions", it said in a statement.
"Almost one quarter of all qualifications sent to us for verification by prospective employers and employment agencies turn out to be problematic to some degree.
"Everything from matric certificates to medical degrees have become fair game."
In the past three months, there had been several instances of bogus doctors, nurses and homoeopaths caught with fake qualifications, the statement read.
Others found to be plying their trade without the requisite credentials included an advocate, a physiotherapist and several teachers.
Forgeries varied from crude photocopies to "extremely elegant" documents complete with wax seals.
"There have been several innovations recently that have complicated the verification process," the company said.
"Among them is the fact that forgers are using the police as unwitting accomplices by getting them to certify forgeries as authentic copies of an original. The police obviously have no way of knowing that the document they are certifying as authentic is in fact a copy of a fraudulent document."
Expert forgers were increasingly entering the market with documents almost identical to those issued by education departments.
Most forgeries occurred with matric certificates, with symbols and subjects "routinely" changed to reflect a passing grade or to include subjects like mathematics and science - sought after by employers.
"The lure of big money, status and the mistaken belief that they can get away with it is responsible for a rapidly growing number of doctors and other professionals misrepresenting their qualifications or stealing those of legitimate, qualified professionals."
One bogus doctor uncovered recently had been practising in East London under the name of a legitimate professional, prescribing drugs to patients and injecting them with used needles.
"Dr" Bertha Lucwaba was sentenced to 15 years in jail.
Another fake doctor was recently arrested in Hammanskraal, outside Pretoria. - Sapa