A Boston-based lender has accused Westport law firm Berkowitz, Trager & Trager of submitting a faulty opinion letter in support of a loan that later defaulted to the tune of $13 million.

In an eight-page complaint filed Aug. 4, UCF I Trust 1 and a trustee claimed Berkowitz Trager misrepresented the ownership interest firm PWSMA 1 held in the borrower. PWSMA 1 was acting as collateral for the loan.

UCFT, a Delaware statutory trust, issued a mezzanine loan to Park Square West Members Associates. A mezzanine loan allows the lender to take an equity or ownership stake in the borrower if they default.