In a regulatory report the company, which has brewing operations in the US and Canada, said the problems related to its previously issued financial statements for the years ended 31 December, 2017 and 2016.

The audit committee and PwC have found an error in the 2016 income tax accounting for inside and outside basis differences related to the company’s partnership in MillerCoors. This resulted in an understatement of its deferred tax liability and income tax expense, and overstatement of net income by $399.1m (£309.5m) for the 2016 financial year.

This was compounded when the deferred tax liability required revaluation in 2017 due to the impacts of the Tax Cuts and Jobs Act, resulting in an overstatement of income tax expense and understatement of net income of $151.4m for the financial year 2017, along with a net cumulative understatement of the deferred tax liability of $247.7m.

In its report to the Securities and Exchange Commission (SEC), Molson Coors said it has determined that a material weakness existed in the company’s internal control over financial reporting as of 31 December, 2018 relating to the design and maintenance of effective controls over the completeness and accuracy of the accounting for and disclosure of the income tax effects of acquired partnership interests.

Specifically, the company did not design appropriate controls to identify and reconcile deferred income taxes associated with the accounting for acquired partnership interests.

Report by Pat Sweet