The home builder confirmed the move in its latest results released today for the year to September 30 2019.
Group chief financial officer Mike Scott said: “In the first half of the year, a non-cash charge of £7.4m was recognised to impair the value of inventories in our Manchester region.
“This was the result of costs accrued over a four-year period not being appropriately recognised in the consolidated statement of comprehensive income.
“Management took a number of steps to rectify this and to ensure the issue was contained in this region, including the appointment of Deloitte LLP to perform a full investigation.
“Disciplinary action was taken against the members of staff involved, none of whom remain employed by the group.”
A positive set of overall results saw completions rise 33% to 5,733 pushing revenue up 21% to £1,237.1m generating pre-tax profit of £203.6m.
Ian Sutcliffe, Group Chief Executive, said: “We have continued our excellent growth trajectory during the past year and have exceeded our expectations in operating margins, return on capital employed and cash generation.
“With strong demand from first-time buyers and ongoing political support, the Board looks forward to delivering continued growth from both of our operating divisions.”