Electrical and refrigeration company Hastie Group will take a $20 million hit to its full year profit after discovering "deliberate" irregularities in its financial accounts.
The company on Friday said an employee deliberately caused the irregularities in Hastie's accounts in the 2008/09 financial year.
The employee had been suspended, the company said.
Other current and former senior management also may have been involved, and may have failed to apply the required financial supervision and review standards, Hastie said in a statement.
Accounting irregularities originally amounting to $3 million were discovered during audits in the six months to December 31, 2011, and were included in the company's loss for that period.
But fresh information received recently by Hastie prompted further investigations which revealed even larger irregularities, the company said in the statement.
"These irregularities date from the financial year 2009 and appear to have resulted from the deliberate actions of a current employee (on suspension) and that, potentially, some current and former senior management may have participated in the irregularities and failed to apply the required standards of financial supervision and review," Hastie's statement said.
Hastie said it would take a charge of about $20 million to its current financial year profit as a result.
The company said it had referred the matter to the corporate watchdog, the Australian Securities and Investments Commission (ASIC).
Hastie said it expected to release more information once it investigations were complete.
The company supplies mechanical, electrical and refrigeration services to the building industry
