The US department of justice has sued Barclays and two former executives on civil charges of fraud relating to the sale of mortgage-backed securities during the run-up to the 2008-9 financial crisis.
Several major US banks, including JP Morgan Chase and Bank of America have already paid millions of dollars to settle similar claims.
Deutsche Bank has reached a $7.2bn (£5.8bn) settlement and Credit Suisse a $5.28bn settlement in the same probe, the banks said today.
A Barclays spokesperson said:
Barclays rejects the claims made in the complaint. Barclays considers that the claims made in the Complaint are disconnected from the facts. We have an obligation to our shareholders, customers, clients, and employees to defend ourselves against unreasonable allegations and demands. Barclays will vigorously defend the complaint and seek its dismissal at the earliest opportunity.