The battle between online listings giants over trade secrets continued Tuesday with the latest round going to Zillow Group (Z), as the judge in the lawsuit agreed to seal in whole and redact key parts of a letter from an anonymous whistleblower claiming former Move executive Errol Samuelson took trade secrets from Move and the National Association of Realtors.

In an ironic twist, the judge said the anonymous source letter contained and violated Zillow’s trade secrets.

On Friday, HousingWire reported that the letter in question submitted in the case “appears to confirm” the contention by Move that Samuelson, now the chief industry development officer for Zillow, took multiple documents and entire databases from his former employer.

Move and the National Association of Realtors filed suit against Zillow on March 17, 2014, after Samuelson, Move's chief strategy officer, resigned from Move on March 5, 2014, and joined Zillow as the company's second-highest paid executive on the same day.

“Zillow has and will continue to act with the utmost integrity in conducting its business and in defending against this litigation,” Zillow Communications Manager Amanda Woolley told HousingWire Tuesday. “News Corp’s recent court filing of a purported ‘anonymous letter’ is full of false and misleading information and was a clear attempt to discredit, disparage and damage Zillow publicly and competitively.

“We have taken swift and appropriate legal action and will be addressing these matters in the courts based on the facts, not unsubstantiated claims,” Woolley said. “We are pleased that, following the court's review of the facts, they have ruled in favor of Zillow's motion to seal information about proprietary systems and data released by our competitor.”

The original lawsuit alleged breach of contract, breach of fiduciary duty and misappropriation of trade secrets and accused Samuelson of misappropriating trade secret information by acquiring it using improper means, and by copying it without authorization.

The lawsuit alleged that Samuelson's knowledge of Move's trade secrets and strategies would make it impossible for him to function in his new job at Zillow without divulging those secrets, but that contention was dismissed in April 2014.