Sabharwal & Finkel principals Rohit Sabharwal and Adam Finkel claim Sorrell made a series of false and defamatory statements about the firm in an interview with an Indian website while discussing the TV ratings case.

NDTV has sued WPP and several of its companies, including Kantar, for more than $810m in damages, claiming that false ratings data produced by TAM Media Research – a company jointly owned by Nielsen and Kantar – had caused it to lose ad revenue.

WPP has said previously that NDTV’s lawsuit is without merit and it has filed a motion to dismiss the complaint. Speaking to LiveMint.com on 24 August, Sorrell is quoted as saying: “This whole thing is mischievous, designed to elicit some financial response from us… This is to extort money from us.”

Sabharwal and Finkel filed for defamation in the New York State Supreme Court on 27 August. They complain that the above statements are false and defamatory as are Sorrell’s references to the law firm being based in Florida, specialising in restaurant law and working on a contingency basis. They say the statements have caused them to suffer various professional injuries.

WPP had previously threatened to sue NDTV for defamation.