PricewaterhouseCoopers is facing investigation by the UK Accounting & Actuarial Discipline Board (AADB) for possible accounting errors and rule violations uncovered after its audits of RSM Tenon Group. The mid-sized corporate finance advisory firm is also being investigated. RSM had to restate its annual accounts in February this year.

RSM Tenon has previously announced it found “significant errors” in its 2010 revenue and declared its pre-tax earnings at £19.1m less than previously stated. At the time the company revealed “a limited number of significant errors and areas were accounting policies had not been properly applied.” Errors included miscalculations for the cost of staff bonuses.

AABD has revealed the investigations pertain to the preparations, approval and audit by PWC of the financial statements for 2009-2010, as well as 2010-2011. At the time RSM Tenon was preparing its admission to the main market at the London Stock Exchange, and much of the documentation containing the errors was in reference to the floatation. A recent acquisition of RSM Bentley Jennison by RSM Tenon will also be probed.

“We will be cooperating fully with the AADB investigation,” PwC said in an emailed statement to Bloomberg. “We will be vigorously defending our audits and other work carried out for the RSM Tenon Group.”

The AABD is the branch of the Financial Reporting Council that deal with high-profile misconduct cases in the UK.