The auditor of many of the companies in Sanjeev Gupta’s network of metals companies has resigned from at least five of them, amid an investigation of its work by UK regulators. London-based King & King has resigned as auditor of the companies in Gupta’s GFG Alliance, a sprawling group of firms under his control. The accountant is under investigation by the accounting regulator, the Financial Reporting Council, for its audits of four GFG companies. Gupta’s businesses have faced intense scrutiny for well over a year after his main financial backer, Greensill Capital, collapsed in March 2021. The UK’s Serious Fraud Office (SFO) announced in May 2021 that it was investigating Gupta Family Group Alliance (GFG Alliance) and Greensill for “suspected fraud, fraudulent trading and money laundering”. The SFO attended GFG offices in April 2022 to request documents, but GFG has denied any wrongdoing and has said it will work with investigators. The turmoil has caused concerns for the future of thousands of workers employed by Gupta. GFG has previously claimed to employ 35,000 people worldwide. The companies that reported auditor resignations on Thursday included Liberty Speciality Steels, Speciality Steel UK, and Liberty Steel Dalzell, according to filings published on Thursday on the UK companies register. Those entities run steel mills in Rotherham and Stocksbridge in South Yorkshire, which employ close to 2,000 people, and another near Motherwell, south of Glasgow. The other businesses that reported King & King’s resignation were Liberty Pressing Solutions (Coventry) and Liberty Steel Distribution, according to a review of businesses that list Gupta as a director. The Financial Times first reported that King & King had begun resigning from GFG firms. A GFG Alliance spokesperson said: “We have parted company with King & King due to overall issues resulting from the collapse of Greensill Capital. We are in the process of appointing new auditors. There is no impact on the operations of any of our businesses.” None of the companies have published annual accounts since those for the year ending on 31 March 2019, meaning accounts for later years are long overdue. Not filing an annual report is a criminal offence, although the maximum financial penalty for late filing is only £1,500 for a private company. It is generally seen as a red flag for other companies carrying out due diligence. Gupta is listed as the director of 77 active companies on Companies House. Accounts for at least 31 of those were overdue on Thursday evening. King & King was approached for comment.