Tycoon Sanjeev Gupta"s commodities empire is being investigated by Britain"s Serious Fraud Office in a probe that encompasses the conglomerate"s links to collapsed lender Greensill Capital, the SFO said on Friday. The probe piles pressure on Gupta, who has been scrambling to refinance his international web of businesses in steel, aluminium and energy after supply chain finance firm Greensill filed for insolvency in March. In a statement, the anti-graft agency 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 Ltd." GFG said it would co-operate fully and would not comment further on the investigation. The SFO said it had no further comment. Greensill Capital lent money to firms by buying their invoices at a discount, but it collapsed in March after one of its main insurers declined to renew its cover. Its sudden failure has resonated around the world, drawing in Swiss investment bank Credit Suisse (CSGN.S), German depositors and former British Prime Minister British Cameron, who was grilled in parliament this week over his lobbying efforts on behalf of Greensill. read more Authorities are starting to home in on both Gupta and Greensill with Britain"s Financial Conduct Authority on Tuesday saying it was formally investigating Greensill"s UK operations as part of global probes. read more Germany"s financial regulator shuttered Greensill"s Bremen-based bank and filed a criminal complaint against it earlier this year saying the lender could not provide evidence of receivables on its balance sheet. GFG was Greensill"s largest client. It said in February it would "collapse into insolvency" if the supply chain finance firm stopped providing it with working capital, Greensill said in its insolvency filing in March. read more Greensill cited a $5 billion exposure to GFG Alliance when it filed for bankruptcy protection in Australia and Britain in March, a source familiar with the matter said on condition of anonymity. SAVIOUR OF STEEL Gupta had been lauded as the saviour of steel in Britain as he bought distressed assets in economically-deprived areas. His group has 35,000 workers, including 5,000 in Britain, and annual revenues of $20 billion. GFG also has operations in Europe, Australia and the United States. Liberty Steel, part of the GFG group, said last week it had appointed a committee to restructure and refinance it. On Friday, GFG said it was making progress in the financing efforts and on Thursday, Gupta"s Wyelands Bank said it was looking at a sale or winding up operations. read more Among the investors burnt in the widespread fallout from Greensill"s collapse were clients of Credit Suisse, who had invested in a $7.3 billion finance fund exposed to debt issued by the finance firm. read more The Swiss bank declined on Friday to comment on the UK fraud investigation, but repeated a comment from last week saying it wanted a credible restructuring plan. "We have asked GFG Alliance for that repeatedly and nothing has been forthcoming."