Investigators from the Serious Fraud Office have requested documents and questioned executives at the British offices of companies owned by the industrialist Sanjeev Gupta, in a sign of deepening legal difficulties for GFG Alliance, his metals and energy group. The fraud agency attended several addresses in England, Scotland and Wales on Wednesday as part of the investigations, the Serious Fraud Office (SFO) said. Locations attended by investigators included Stocksbridge, Hartlepool and Scunthorpe in northern England and Newport in Wales, according to a person with knowledge of the situation. The SFO did not issue a warning of Wednesday’s operation, relying on powers that allow it to require witnesses to answer questions as well as to produce documents. It is understood that the companies complied with requests for information, and that the investigators did not force entry into any premises. The SFO revealed its investigation in May 2021, shortly after the collapse of GFG’s main financial backer, Greensill Capital, prompted intense scrutiny on the company. The SFO said it was investigating “suspected fraud, fraudulent trading and money laundering in relation to the financing and conduct of the business of companies within the Gupta Family Group Alliance (GFG), including its financing arrangements with Greensill Capital UK”. Gupta’s main UK assets are a series of steel plants under the Liberty Steel banner, including large operations at Rotherham and Stocksbridge in South Yorkshire and smaller facilities in Wales and the Midlands, as well as an aluminium smelter in Scotland. Gupta is listed as a director of 77 UK companies, although many are ultimately controlled by companies in Singapore. The SFO’s action follows a raid by French prosecutors last week, who said they are investigating allegations of “misuse of corporate assets” and “money laundering”. The French government has grounds to believe GFG Alliance has “misappropriated” funds from a steel plant in Romania, according to court documents in a separate case involving another of Gupta’s companies. A person with knowledge of the operations on Wednesday said the SFO’s actions did not constitute a “raid”, arguing that it was a standard part of the process of the investigation. The SFO said: “On Wednesday 27 April, teams of SFO investigators across the UK issued notices under section 2 of the Criminal Justice Act 1987 at addresses linked with Sanjeev Gupta’s GFG Alliance, also known as the Liberty House Group of companies. “Teams attended trading addresses earlier this morning, issuing section 2 notices to request documents including company balance sheets, annual reports and correspondence related to the SFO’s investigation. “Investigators spoke to executives at multiple addresses, who cooperated with the operation. As the investigation is ongoing, the SFO can provide no further comment.” A spokesperson for GFG declined to comment. Jeff Kabel, an executive hired to turn around the struggling Liberty Steel businesses, sent an internal memo to employees on Wednesday, saying the group would comply with any information requests from the SFO. The memo also advised Liberty Steel employees to reread the group’s “very strict information and document preservation policies”. “We have consistently rejected any wrongdoing on our part and pledged to cooperate fully to ensure they can conclude their investigations as quickly as possible,” Kabel wrote in the memo. “We are encouraged that the investigation is now progressing and is moving closer to a conclusion. Please rest assured that this does not impact the operation of our companies and we must continue to focus on our business plans and operating safely.” This article was amended on Wednesday 27 April 2022 to change the word “seized” to “requested” in the headline and introduction.