Healthcare giant GlaxoSmithKilne will plead guilty and will pay a record-breaking $3bn (£1.9bn) to settle the largest case of healthcare fraud in US history.
The settlement includes $1bn in criminal fines and $2bn in civil fines following an investigation into the company's marketing practices for nine of its products.
The company pleaded guilty to two counts of introducing misbranded antidepressant drugs Paxil and Wellbutrin and one charge of failing to report safety data about the diabetes drug Avandia to the Food and Drug Administration (FDA).
Prosecutors claimed GSK encouraged use of Paxil for children although it was not approved for use by anyone under the age of 18.
The FDA said that between 2001 and 2007, GSK failed to report on two studies of the cardiovascular safety of Avandia.
James Cole, deputy attorney general, said: "Today's multibillion-dollar settlement is unprecedented in both size and scope. It underscores the administration's firm commitment to protecting the American people and holding accountable those who commit health care fraud.
"At every level, we are determined to stop practices that jeopardise patients' health, harm taxpayers, and violate the public trust - and this historic action is a clear warning to any company that chooses to break the law."
GSK CEO Sir Andrew Witty said: "Today brings to a resolution difficult, long-standing matters for GSK.
"Whilst these originate in a different era for the company, they cannot and will not be ignored. I want to express our regret and reiterate that we have learnt from the mistakes that were made."