"The tone of the brief reads like an indictment," Apple General Counsel Bruce Sewell told reporters on a press call, referring to a response filing the Justice Department submitted earlier on Thursday that accused Apple of making "false" statements.
The new filing relies on thinly sourced news reports to inaccurately suggest that Apple had colluded with the Chinese government to undermine buyers' security, Sewell said.
The filing was the Justice Department's last chance to make its case ahead of a hearing set for March 22 in a Riverside, California federal court. The clash has intensified a long-running debate over how much law enforcement and intelligence officials should be able to monitor digital communications.
In its brief, prosecutors noted that Apple has attacked the FBI investigation as "shoddy" and portrayed itself as "the primary guardian of Americans' privacy."
Apple's rhetoric "is not only false, but also corrosive of the very institutions that are best able to safeguard our liberty and our rights: the courts, the Fourth Amendment, longstanding precedent and venerable laws, and the democratically elected branches of government," prosecutors added.
The government said Apple "deliberately raised technological barriers" to prevent execution of a warrant.
Apple has said the government's request would open the company to pressure from repressive regimes to provide similar assistance. But the Justice Department on Thursday questioned whether Apple is actually resisting such requests.
© Thomson Reuters 2016