According to the Justice Department’s lawsuit, Guidant had sold the defibrillators even though it knew they were defective and hid the device problems from patients, doctors and the US Food and Drug Administration (FDA).

The department alleged that Guidant knew about a potentially life-threatening defect associated with an implantable cardiac device as early as April 2002, and also knew about a similar defect in another device as early as November 2003.

The lawsuit stated that Guidant did not fully disclose the problem to doctors and the FDA until May 2005.

Boston Scientific spokesman Paul Donovan said the company has been aware of the government’s interest in this civil matter, and plans to respond to the government’s allegations and claim for damages in the appropriate fashion.

Last year, Guidant had agreed to pay $296m in fines in a settlement to the Justice Department for withholding information related to the heart devices from the FDA.

Guidant was acquired by Boston Scientific in April 2006 for $27bn.