The chairman of the influential Business Committee of MPs has written to steel magnate Sanjeev Gupta accusing him of being “deeply discourteous” over his refusal to appear before them.

Darren Jones, who chairs the committee which is investigating Liberty Steel and the future of the UK steel industry, said the businessman must explain the way his empire is run, sending him a list of 36 questions.

The tycoon had been asked to appear before MPs but refused – only agreeing to send written evidence to the committee.

Mr Jones wrote: “The public will infer what they will from your refusal to appear.

“Given the broader importance of these issues, as well as their centrality to our inquiry, you will appreciate the need for detailed and comprehensive answers.

“I expect your written submission to answer each individual question in turn and will not accept attempts to avoid questions by providing sweeping general answers in a format to your liking.”

As part of their investigations, MPs are looking at the collapse of Greensill Capital, which had exposure of around 5 billion US dollars (£3.6 billion) to Mr Gupta’s GFG Alliance after providing many loans.

GFG is unusual in that the firms are linked through their ownership by Mr Gupta and his family, but they are not formally part of a group.

In total, GFG’s companies – which includes Liberty Steel – were paid £350 million across seven Government-backed Coronavirus Large Business Interruption Loan Scheme (CLBILS) loans from Greensill.

Greensill tried to secure a loan from the Bank of England through a separate scheme, with former prime minister David Cameron lobbying Treasury officials and ministers. He denies any wrongdoing.

GFG’s structure has faced criticism from MPs for being too opaque and Mr Jones has asked Mr Gupta to explain why he opts for it to be set up in such a way.

Questions to the businessman cover issues including allegations that GFG used fake invoices and so-called circular financing.

MPs also want to know how the Government loans were spent by Liberty Steel and if any more money was received beyond that supplied by Greensill Capital.

Mr Gupta is also asked to explain whether GFG Alliance companies were divided into separate legal entities in order to bypass the £50 million lending limits on CLBILS loan guarantees.

And MPs want to know whether Mr Gupta personally lobbied any current or former Government ministers or officials.

Other questions involve Liberty Steel’s current financial position, its relationship with Wyelands Bank – which is also part of the GFG Alliance – and auditing processes.

Mr Jones said: “In the evidence we have heard so far in our inquiry, a story has emerged of the unusual extent to which Sanjeev Gupta personally controls the finances of Liberty Steel and its associated companies.

“Liberty Steel companies have received hundreds of millions in taxpayer-backed loans and the GFG Alliance has been in receipt of millions more in Government guaranteed-funding.

“Given the taxpayer’s considerable exposure to GFG Alliance, it is right for Parliament, and the public, to expect Mr Gupta to emerge from behind his lawyers and come forward with meaningful responses to key questions relating to Liberty Steel and the GFG Alliance.”

Several other investigations are taking place into GFG Alliance and Greensill Capital alongside the one by the Business Committee.

These include inquiries by the Treasury Select Committee, the Public Accounts Committee and the Public Administration and Constitutional Affairs Committee.

The Serious Fraud Office has launched an investigation into GFG and its financing arrangements with Greensill.

The National Audit Office is probing Greensill’s involvement in a Government-backed pandemic loan scheme, which is also being looked at by the British Business Bank.

Lawyer Nigel Boardman is investigating the Government’s use of supply chain finance, the Cabinet Office is reviewing the Lobbying Act, and the Financial Conduct Authority (FCA) is probing “potentially criminal” allegations about the failure of Greensill.

The accounting watchdog, the Financial Reporting Council (FRC), is also investigating the auditors of Greensill and Wyelands Bank.

A spokesman for GPG Alliance in response referred to a letter sent by Mr Gupta on July 1, which said: “Should the Committee wish to ask follow up questions in response to our submissions, I would be happy to receive those in writing and I will respond as fully we are able.”