In a letter sent to a New York judge, FanDuel’s lawyers said they were filing the arbitration due to Eccles “repeatedly and flagrantly” breaching his November 2017 separation agreement with the business.

He did this, the lawyers argued, by actively recruiting and assisting plaintiffs in his lawsuit against the company he co-founded in 2009, which later became the largest regulated sports betting operator in the US.

Eccles told NEXT.io: “KKR, Shamrock and FanDuel’s former board are clearly fearful of confronting their misdeeds that our lawsuit has brought to light. Instead of confronting the allegations in court they have now decided to sue me for bringing the lawsuit in the first place! 

“They believe that I have no right to assist former FanDuel employees recover what is rightfully theirs. This is nothing more than an effort by the defendants to avoid answering the serious allegations that have been made against them. Last year New York’s highest court ruled against them and stated that the allegations demanded answers. And so do we.”

Eccles’ lawsuit, currently progressing through the New York Supreme Court, alleges private equity firms including Shamrock Capital Advisors and KKR conspired to squeeze out FanDuel’s ordinary shareholders, including the founders, early investors and employees, by recommending an artificially low valuation for the company during its 2018 sale to Paddy Power Betfair.

Those shareholders received $0 following the acquisition, while preferred stockholders walked away with billions after selling their stakes several years later.

FanDuel’s attorneys’ version of events, however, suggests that KKR and Shamrock saved FanDuel by helping shepherd through the deal, despite Eccles’ previous rocky leadership.

The lawyers wrote in the arbitration: “Mr. Eccles slapped the hand extended to him by helping over 100 other plaintiffs bring two different lawsuits against FDI and the KKR/Shamrock Investors (among others), that seek hundreds of millions of dollars in purported damages arising out of the very acquisition that saved FanDuel from the mess Mr. Eccles had created.”

As a result of Eccles’ alleged breach of his separation agreement, FanDuel said it wanted him to disgorge around $8m worth of payments he received under the deal, as well as secure an order for him to stop helping the plaintiffs in their case.

The lawyers added: “The arbitration thus could significantly affect this action. FDI and the KKR/Shamrock Investors may need to ask the court to grant such injunctive relief in the first instance or, at minimum, to enforce any arbitration award against Mr. Eccles.”