Reckitt Benckiser has agreed to pay up to $1.4bn to the US Department of Justice (DoJ) and the Federal Trade Commission (FTC) to resolve a probe against its former pharmaceuticals business Indivior over an illegal scheme to promote opioid addiction treatment sales.

Indivior spun out of Reckitt in 2014 and allegedly ran a scheme to avoid competition from lower-priced generic to its Suboxone Film, used to reduce opioid withdrawal symptoms in patients recovering from addiction.

As part of the settlement, Reckitt will pay nearly $1.35bn to resolve the DoJ’s criminal and civil claims, noted Reuters. The company will pay an additional $50m to resolve FTC claims about violation of antitrust laws.

FTC noted that regulatory exclusivity for Suboxone was set to expire in 2009, and to avoid competition from generics the companies developed a dissolvable oral film formulation of the treatment.

To ensure that doctors and patients switch to the new product, Reckitt was accused of making claims that the film version was safer than tablets as children are less likely to be accidentally exposed to the film.

In addition, the complaint claimed that the companies filed a petition with the US Food and Drug Administration (FDA) including the same safety claims and asked for rejection of any generic tablet application.

Commenting on the settlement, Reckitt said: “While RB has acted lawfully at all times and expressly denies all allegations that it engaged in any wrongful conduct, after careful consideration, the board of RB determined that the agreement is in the best interests of the company and its shareholders.”

This settlement is the largest related to the opioid epidemic in the US, with Purdue Pharma, Teva and Insys agreeing to pay $270m, $85m and $225m respectively.