According to Sky News, representatives of the Official Receiver sent the letter earlier this month in a bid to advance the case of Carillion, which collapsed in early 2018 owing almost £7bn.
The pre-action letter signals a further step closer in the official process required to be taken before the claim can be taken to court.
Moreover, Carillion’s liquidators last month struck a deal with Litigation Capital Management (LCM) to fund the lawsuit.
At the time, LCM said that the claim had risen from KPMG’s conduct of its audits of the construction company’s financial statements, which supposedly led to in excess of £250m in losses for the group.
While KPMG declined to comment, a source close to the firm reportedly claimed that no official claim has been lodged with the courts.