WASHINGTON (Reuters) -The U.S. filed a civil lawsuit on Tuesday against private equity firm KKR & Co ( KKR ), "for repeatedly flouting the premerger antitrust review process," alleging the company avoided antitrust scrutiny for at least 16 deals from 2021 to 2022.

"Through document omissions, alterations, and failures to report deals, KKR threatened the integrity of the (Antitrust) Division's premerger reviews and, in some cases, obscured the market impact of its deals and serial acquisitions," said Justice Department official Doha Mekki.

In a related lawsuit filed against the DOJ in federal court in Washington on Tuesday, KKR said, "After a sweeping investigation that has spanned nearly three years - with which KKR fully cooperated - the purported filing 'errors' the Antitrust Division has identified are trivial."

"Not a single alleged 'error' was material to or interfered with any merger review," KKR added.