The drug group said it had reviewed the claim and noted comments in the press by Reckitt Benckiser that it "regularly takes certain procedural steps to preserve potential claims."
Indivior added that as yet it has not been served with a claim and, based on the information available to it, strongly believes that the claim is without merit and that it has strong grounds for defending against the claim should it be served.
Indivior added it will 'fully and vigorously' defend itself in any proceedings related to the claim if it is served, said the statement.
The indemnity was set up in 2014 when the two companies demerged.
Since then, Indivior has been embroiled in numerous legal actions related to its opioid dependency treatment Suboxone and that resulted in it agreeing to a settlement of US$600mln with the Department of Justice and other Federal and State bodies in July.
Last year, Reckitt Benckiser agreed to pay around US$1.4bn to the US authorities in an effort to draw a line under the issue.