Goldman Sachs Group Inc's former director Rajat Gupta is liable to reimburse $6.22 million to the investment bank to allow the bank to cover its legal expenses related to his insider-trading case, a federal judge ruled on Monday.

Last year, 64-year-old Gupta was convicted of sharing confidential information he had learned at the bank's board meetings with hedge-fund manager and his friend Raj Rajaratnam. He also exposed a $5 billion investment by Warren Buffett-owned Berkshire Hathaway Inc. at the peak of the economic slump.

The investment bank had requested the court in Manhattan to help it recover money that it had to pay to law firm Sullivan & Cromwell to fight Gupta's criminal case. The bank cited the federal Mandatory Victims Restitution Act that requires restitution in certain fraud cases.

Gupta opposed the restitution but US District Judge Jed Rakoff sided with the bank and ruled that the expenses that Goldman suffered were the direct and foreseeable product of the probe and prosecution of Gupta's offense.

The judge also allowed the bank to recover legal costs related to US Securities & Exchange Commission (SEC) civil case against Gupta.

However, Rakoff added that Goldman didn't deserve all it sought. The judge said that the bank was entitled to 90 per cent of what it sought.

Meanwhile, Gupta is appealing his June 15, 2012 conviction and two-year jail term for exposing the confidential corporate information.