An outside audit has found that Metro violated federal contracting rules when it awarded a contract to a McLean information technology company, the latest controversy surrounding the more than $12 million contract.

The audit, from CliftonLarsonAllen, found that the agency’s contract with Metaformers “did not follow federal procurement compliance requirements with respect to open competitive bids,” according to a presentation that the firm is scheduled to make to board members Thursday. Metro hired the firm to audit its books as part of an annual review.