KPMG is facing a fine in excess of £15m for its “grave misconduct” in relation to the sale of mattress company Silentnight to private equity firm HIG in 2011.

A draft report from the disciplinary tribunal of the Financial Reporting Council found that KPMG and former restructuring partner David Costley-Wood advised both Silentnight and HIG despite an “obvious” conflict of interest between the two businesses between August 2010 and January 2011.