The Accountancy and Actuarial Discipline Board is to examine Lehman's financial statements as well as the use of controversial accounting practices such as Repo 105, a measure which allowed the bank to hide debts from its balance sheets.
Ernst & Young stated it is confident it will be vindicated by the probe.
"[Our] audit opinion stated that Lehman's financial statements for that year were fairly presented in accordance with the relevant accounting standards and we remain of that view," a statement from the company said.
In March, court-appointed examiner Anton Valukas – who spent a year investigating how the collapse of Lehman Brothers occurred – said the use of the Repo 105 "accounting gimmick" had allowed the firm to keep around $50 billion worth of debt of its balance sheet in the first six months of 2008.
He criticized the bank's executives for giving permission for the misleading financial statements to be published.