A newly filed amendment to a lawsuit brought by a former WPP executive claims that Sony conducted its own WPP Sony rebate investigation and concluded the ad agency giant had withheld rebates from clients through what Sony called a ‘global crime scheme’ spanning multiple markets, including China.
The allegation surfaces in an amended complaint filed by Richard Foster, who spent 17 years at GroupM, ending as global CEO of its Motion Content Group division, which co-produced Love Island and managed roughly $500 million in annual entertainment investment, according to Digiday. Foster originally filed the lawsuit in November, accusing the company of retaliating against him and firing him after he raised concerns that WPP’s media investment division was allegedly running an improper global kickback operation.
What the WPP Sony rebate investigation allegedly found
According to the amended complaint, Sony presented its findings to WPP in 2025 in a detailed analysis. The lawsuit contains a purported slide from Sony’s presentation titled ‘impact for WPP Advertisers, China 2024,’ which claims that approximately $110 million was passed back to clients in that year, while $350 million remained in WPP’s rebate pool ‘for later utilization’ by the company. A separate purported Sony slide described the practice as a ‘fraud scheme’ run in China and other markets, attributing its design to senior global WPP executives.
Sony drew its findings from the work of independent investigators who attended a criminal trial in China involving WPP executives and from interviews with former WPP and GroupM executives. The lawsuit says Sony supported its conclusions with contractual language regarding rebate policies, transaction-level financial reporting, internal emails regarding rebate amounts, and documentation of WPP tracking systems. GroupM was rebranded to WPP Media last year.
The practice, as alleged, places WPP’s own interests ahead of its clients’: engineering a way to use advertising budgets to maximise its own profits without client consent. Foster alleged that the operation was not confined to China and was deployed as part of a global model through which GroupM improperly retained roughly $1.5 billion to $2 billion in profits from rebate deals over five years, by his estimation. The amended complaint says Sony’s findings corroborated ‘years of whistleblowing’ from Foster, who is seeking at least $100 million in damages.
Timeline: firing, stock drop and a draft complaint
The timing of Foster’s departure adds context that is now part of the public record. Digiday reported that Foster was fired on 10 July 2025, the day after WPP’s stock dropped 18% on a trading update disclosing serious deterioration at WPP Media. Foster’s counsel then sent WPP a draft complaint on 10 October 2025 (more than two months before filing) and threatened to go public unless GroupM agreed to a large severance payment within 30 days, according to Digiday.
In the latest filing, Foster says he refused a ‘seven-figure termination package which included an obligation of silence regarding the company’s undisclosed rebate practices.’ William A. Brewer III, partner at Brewer, Attorneys & Counselors and lead counsel to Foster, said in a statement: ‘Richard Foster asked a question any agency should be prepared to answer: Are your profits derived from loyal service to your clients, or not?’
WPP filed a motion to dismiss the original lawsuit, arguing that Foster failed to state a legally sufficient claim while also objecting on jurisdictional grounds. The company declined to comment on the alleged Sony review and said in a statement that the amended complaint, filed days prior to an upcoming court hearing, is an attempt to avoid the case’s dismissal. ‘Both complaints are baseless and without merit, and WPP will be re-filing an updated motion to dismiss,’ WPP said. ‘We have confidence that this matter will be resolved through due legal process.’ A Sony spokesperson said the company does not comment on pending litigation.
China criminal proceedings and the broader rebate question
WPP’s media operations in China have already faced legal scrutiny through a separate channel. Bloomberg reported that Di Fei, the former GroupM China chief investment officer, was sentenced to life in prison for taking bribes totalling $176 million with his ex-colleagues. Di Fei is appealing the ruling, Bloomberg reported in June. WPP has said it is aware of the court’s sentencing of its former employees and has cooperated fully with the relevant authorities.
Media rebates are not inherently illegal, though they raise transparency and accounting issues when not properly disclosed. A US ad industry trade group previously warned that rebates could amount to a breach of contract or fraud if not disclosed to the client or if advertisers were deceived about the practice. Advisory and consulting firm Madison and Wall recently estimated that so-called principal media, where agencies purchase a large volume of inventory at a discount, resell it to clients and make a margin on that resale, accounts for a ‘high single-digit or low double-digit’ share of large-brand and agency activity in the US. Agencies argue the model is often more cost-effective for clients; critics say it can create conflicts of interest, incentivising agencies to steer marketers toward inventory the agency has already bought rather than what best suits their campaign objectives. The WPP Sony rebate investigation, as described in Foster’s amended complaint, takes that structural tension out of the abstract and into a courtroom, with WPP’s re-filed motion to dismiss the next procedural moment to watch.