(Adds chief denying any guilt, background and byline) By Jason Lange MEXICO CITY, Nov 1 (Reuters) - One of Mexico's top police officers has quit after an aide was accused of working for a leading drug cartel, the security ministry said on Saturday. Gerardo Garay, acting federal police commissioner, has stepped down and said he will cooperate with an organized crime investigation, a ministry spokesman said. One of Garay's top lieutenants is being investigated by police on suspicions he was offering protection to the Sinaloa cartel, one of Mexico's main drug gangs. "I am resigning because in the bloody fight against organized crime, it is our duty to strengthen institutions, which means it is essential to eliminate any shadows of doubt regarding me," Garay said late on Friday. About 4,000 people have been killed in Mexico this year as gangs vie for control of the drug trade and security forces take on the cartels. Garay's office was allegedly letting the Sinaloa gang move drugs through Mexico City's international airport, Mexican media reported, although the federal Attorney General's office said Garay was not formally under investigation himself. Garay denied he committed any crimes. Mexican authorities have long been dogged by allegations top officials are on the payroll of the cartels that supply Americans with hundreds of tons of cocaine every year. Police recently arrested two top anti-drug officials accused of taking bribes of up to $450,000 a month to leak intelligence to a drug trafficking cartel. U.S. Customs and Border Protection also arrested a senior Mexican immigration official on the Arizona border last Sunday, accusing him of smuggling marijuana. Mexican President Felipe Calderon has made cleansing the country's police forces a priority in his fight against drug gangs smuggling narcotics to the United States. But low wages, shoddy equipment and rising insecurity in the face of the drug war have made that task increasingly difficult. Calderon has sent more than 40,000 troops across Mexico to fight the drug gangs but despite capturing several drug lords, drug violence continues to spiral out of control. The country's drug cartels smuggle Colombian cocaine and locally produced marijuana into the United States, though some gangs are moving into the methamphetamine trade to meet growing U.S. demand for that drug. (Additional reporting by Tomas Sarmiento)
Mexican legislators stand around the Congress podium with a banner against a proposed energy reform package in Mexico City October 28, 2008. Leftist deputies stormed the podium of Mexico's lower house ...
