text: Buenos Aires fraud cops held in extortion racket . BUENOS AIRES , Argentina 1996-08-29 Thirteen senior police officers from the fraud squad of Buenos Aires province have been arrested on charges of running an extortion racket , security officials said on Thursday . They included all the top officers from the fraud division of the north of Buenos Aires province , including Commissioner Juan Carlos Lago . Police were seeking a 14th officer . La Nacion newspaper said the officers were suspected of demanding bribes of $ 50,000 to $ 500,000 from companies being investigated for tax evasion in order to " lose " their files . The credibility of the Buenos Aires provincial police , the largest force in Argentina , has been undermined this year by scandals that included the indictment of three officers for links to the 1994 bombing of a Jewish community centre and the arrest of an entire drugs squad for drug trafficking . Alberto Piotti , security chief of Buenos Aires province , told local television that 3,600 dishonest officers had been purged from the force 's ranks in the past five years . " It is an ongoing task . And these investigations into police corruption are only possible because there are people brave enough to denounce them , " Piotti said , promising a major overhaul of the provincial police next month .