The government announced the findings on 27 November as part of a report on the first 100 days of Mexican President Calderon’s “Operation Cleanup”, an anti-crime initiative.

The tests, which aimed to “root out corrupt, incompetent and unfit officers”, involved “lie detectors, drug tests, psychological profiling and tests of personal wealth”, reports AP.

In addition to revealing corruption at the federal level, Operation Cleanup also discovered “widespread corruption on the state government level and wherever drug cartels operate,” details Agence France-Presse.

Earlier in November, the chief of Mexico’s organised crime unit, Noé Ramírez Mandujano, was arrested and accused of accepting bribes from a drug cartel, writes The New York Times. According to the same article, “six other high-ranking officials have been charged in the investigation” and “the current and former directors of Interpol’s Mexico office have also been arrested.”

In an interview with the Financial Times, Gustavo Madero, Mexico’s Senate President, said that “nobody should be surprised by the extent to which drugs cartels have managed to permeate the upper echelons of the country’s security forces.” Adding that the drug gangs have been “around for decades.”

“To win the war on crime we need honest and trustworthy police departments. That’s why we must continue to purge and strengthen all the police forces in the country,” said Calderon (AFP).

However, The Economistraises the concern that the army, which has been temporarily deployed while more police were recruited and trained, is being corrupted. Guillermo Zepeda of CIDAC, a Mexican think-tank, told the newspaper: “We may end up without a trustworthy police and without a trustworthy army.”

On 28 November, the Mexican Security Council released a poll that claims “87 percent of crimes went unreported, indicating public distrust of the police and justice system,” according to AFP.