(Reuters) - Greensill Capital’s administrator has been unable to verify invoices underpinning loans to Liberty Steel owner Sanjeev Gupta, the Financial Times reported on Thursday. Greensill’s administrator, Grant Thornton, has received denials from companies listed as debtors to the steel group stating that they had never done business with Gupta, the FT report added. Insolvent finance firm Greensill collapsed last month, days after losing investor funding and insurance coverage for its supply chain financing business. Liberty is part of the GFG Alliance, a conglomerate owned by the Gupta family and one of the biggest customers of Greensill Capital. Grant Thornton and GFG Alliance declined to comment on the report. Reuters was not immediately able to reach Greensill Capital. Grant Thornton, which is looking to regain the money owed to Greensill in its role as administrator to the collapsed firm, last month approached companies that were listed as debtors to Gupta’s Liberty Commodities trading firm, the FT report added. Earlier on Thursday, Gupta cautioned creditors against pulling the plug on Liberty Steel, saying he had garnered huge interest from financiers willing to refinance billions of dollars in debt owed to failed lender Greensill Capital. He did not give details on any specific offers.