Lawsuit alleges Sony investigated WPP's media operation and said it ran a 'global crime scheme'

Toni Anne Barson/Getty Images for iHeartMedia A new legal filing says Sony hired investigators to probe WPP's media rebate practices. Sony's review said that WPP ran a "global crime scheme" and improperly withheld rebates, the filing alleges. WPP declined to comment on the alleged Sony review and said that the lawsuit referencing it is "baseless." A new filing in a lawsuit from a fired WPP executive alleges that Sony, one of the ad giant's major partners, investigated the company and…