According to various estimates, there are anywhere between 300 to 800 small and big private detective agencies in the city. So, even though the Delhi Police’s crackdown on the “illegal activities” of some private detective agencies may have forced some sleuths to go underground, business is booming for hundreds of agencies, which have mushroomed in the city. Of late, some private detective agencies have been in the news for illegally obtaining call detail records (CDRs) for their clients. “Demands for post-matrimonial probe far outdo the pre-matrimonial ones,” says Puri, whose daughter Tanya too heads a separate detective agency. This is only one of several requests the city’s private detectives receive from their clients.