Everything about the accounting black hole, believed to be as large as £20m, at cake shop chain Patisserie Valerie makes for uncomfortable reading.

Chris Marsh, finance director of the chain’s owner Stonebeach, has been suspended and the business needs “an immediate injection of capital” to continue trading after uncovering “significant, and potentially fraudulent, accounting irregularities”.

It follows an HMRC winding-up petition against one of the group’s principal subsidiaries that was launched in September as the tax collector seeks £1.14m in overdue taxes.

Questions need to be put to entrepreneur Luke Johnson, who owns 37% of the firm- through his vehicle Risk Capital Partners- which employs 2,500 people at its 200 outlets and was valued at £440m at the start of the week.

Auditor Grant Thornton will also come under the microscope, especially over its scrutiny of cash-reconciliation processes at the firm.