SHERLOCK HOLMES once remarked that: “It is my business to know what other people don’t know.” These days, detective work is a huge business. Thanks to globalisation, there is a lot that companies would like to know but don’t, such as: is our prospective partner in Jakarta a crook?Corporate detectives sniff out the facts, analyse them, share them with clients and pocket fat fees. Yet, oddly for a multi-billion-dollar industry devoted to discovering the truth, little is known about private investigators. So your correspondent took up his magnifying glass and set off in pursuit of the bloodhounds of capitalism.The best-known is Kroll, founded by Jules Kroll, a former assistant district attorney, in 1972. Along with a dozen or so rivals, it can undertake assignments anywhere in the world, at short notice, deploying teams of former cops and prosecutors, computer whizzes, accountants, investigative journalists and others. These firms are the big dogs of private detection. The industry has, ahem, a long tail of thousands of smaller ones. The precise number is unknown since the business is unregulated in some countries.There is plenty of work to go round….