The number of officers scoring a "not recommendable" rating on the tests averaged 49 percent nationwide, well above the 42 percent who got a "recommendable" rating.

The tests _ which involved lie detectors, drug tests, pyscohological profiling and tests of personal wealth, among other measures _ were intended to root out corrupt, incompetent and unfit officers. The report did not break down how many officers failed each category.

In Baja California, home to the border city of Tijuana, some 89 percent of police tested failed, and only 4 percent were judged "recommendable." Officers there have been periodically disarmed, detained and investigated by federal investigators and army troops on suspicion of aiding drug traffickers.

The report comes amid a continuing federal investigation that in recent weeks has revealed the worst corruption scandal in Mexican law enforcement in a decade, with more than a dozen high-ranking officials _ including the country's top anti-drug prosecutor _ detained on suspicion of passing security information to drug cartels.

The test have been administered to more than 56,000 state and municipal policemen so far this year, President Calderon told Congress on Thursday.

Of those, about 27,700 were deemed unfit for police work, and 23,380 were approved.

As many as two-thirds of police failed security tests in a half dozen states. It was unclear whether they would be subject to further investigation, retraining or dismissal.

Mexico has about 375,000 police officers at all levels.

Police vetting has been problematic in Mexico. Labor laws sometimes make it hard to fire officers and it can be difficult to find qualified candidates in some areas.