Amazon used a secret algorithm that essentially helped the company raise prices on other online sites and “destroyed” some internal communications as the Federal Trade Commission was investigating the company, according to a newly unredacted portions of the agency’s antitrust lawsuit against the e-commerce giant.

The new excerpts, unveiled Thursday, alleged company executives intentionally deleted communication by using a feature on the popular app Signal that makes messages disappear.

By doing this, the FTC said Amazon “destroyed more than two years” worth of communications from June 2019 to “at least early 2022” despite instructions it gave Amazon not to do so.

In a prepared statement Amazon spokesperson Tim Doyle called the FTC’s claim “baseless and irresponsible.”

“Amazon voluntarily disclosed employee Signal use to the FTC, painstakingly collected Signal conversations from its employees’ phones, and allowed agency staff to inspect those conversations even when they had nothing to do with the FTC’s investigation,” Doyle said.

The FTC and 17 states sued Amazon in September alleging the company was abusing its position in the marketplace to inflate prices on and off its platform, overcharge sellers and stifle competition. Amazon is accused of violating federal and state antitrust laws, but the company has responded with a full-throated defense of its business practices.

The antitrust case is the most aggressive move the government has taken to tame the market power of Amazon and comes as the FTC has been taking big swings against tech companies.

The unredacted excerpts of the lawsuit disclosed on Thursday also provided more details on a talked-about algorithm, which was previously reported by The Wall Street Journal and former Vox reporter Jason Del Ray.

“Aware of the public fallout it risks, Amazon has turned Project Nessie off during periods of heightened outside scrutiny and then back on when it thinks that no one is watching.”

— Federal Trade Commission