A leading nationwide mortgage lender and servicer NewRez—the largest holder of clean-up call rights for pre-2008 residential mortgage backed securities (RMBS)—has “deliberately and systematically” underpaid defined call prices for RMBS trusts, a new lawsuit alleges.

Plaintiff HBK Master Fund filed suit against NewRez LLC and Deutsche Bank National Trust Co. on Dec. 14 in the commercial division of Manhattan Supreme Court. The complaint claims the pattern of valuation used by NewRez (NRZ) shorted trust investors by some $3.25 million.