Australia’s Leighton Holdings has dismissed a senior manager from its offshore division following an internal review of possibly corrupt payments made in Iraq.

In a 5 July statement to the Australian Stock Exchange, the company said its investigation highlighted failures to meet governance standards for the documentation of contracts.

The name of the manager has not been disclosed.

Australia’s Federal Police have been investigating a $518m contract, which was awarded to Leighton Offshore for the expansion of crude oil export facilities in the south of Iraq, after they had been alerted to possible illegal conduct by the firm in February.

Investigations by the Iraq government concluded that there had been no irregularities in the award process and in April, but the Australian authorities have continued their own enquiry.