The Sunday Mail revealed the rural economy secretary met with both men for dinner at a Glasgow restaurant, but no officials were present and no notes were taken – a strict rule for any meeting on government business.
No emails, texts or phone records exist linked to the dinner at Cail Bruich in 2017, the Scottish Government and Mr Ewing claimed.
Mr Gupta, Greensill and the Scottish Government struck complex multi-million pound financial deals for major state support used by Mr Gupta to purchase metal and power plants in Scotland.
However, the firm GFG Alliance is now in crisis due to the collapse of Mr Greensill’s finance firm, Greensill capital, which was Mr Gupta’s biggest financial backer prior to administration.
The SNP claimed the meeting between the men was “properly recorded” and said “attempts to make mischief around this issue are utterly baseless”.
A spokesperson said: “Civil servants do not attend every dinner or engagement a minister goes to – that would be a ludicrous waste of public money – and the ministerial code does not require them to.”
Scottish Labour’s economy spokesperson, Monica Lennon, said Mr Ewing had “serious explaining to do” about the dinner and called for an investigation into whether the minister had breached the ministerial code.
She said: “Scottish taxpayers could end up paying out hundreds of millions of pounds over the next 25 years as a result of a deal involving these businessmen – and it’s increasingly unclear how safe that investment is or whether it ever represented good value for money.
“What on earth was a Cabinet minister doing having a cosy dinner at a posh west end restaurant without any officials present when government business was clearly on the agenda.”
In response to a freedom of information request, the Scottish Government confirmed the dinner was attended by Mr Ewing, Mr Greensill, and Mr Gupta, alongside two colleagues of the businessmen, Jay Hambro and Tim Haywood.
The Scottish Government added ‘themes of discussion’ were recorded by Gupta’s firm GFG Alliance, with notes stating that Ewing had reported a “positive relationship” focused on “derisking” both parties in relation to plans for growth at Lochaber.
No records on who paid for the dinner were taken.
The news comes amid revelations David Cameron took Mr Greensill for a “private drink” with Health Secretary Matt Hancock to discuss a payment scheme later rolled out in the NHS.
The Sunday Times also reported that the Treasury reconsidered Mr Greensill’s application for an emergency coronavirus loan after the former prime minister messaged a senior adviser to Boris Johnson.
Mr Cameron was said to have described the decision to exclude his employer’s firm, Greensill Capital, from the multibillion-pound scheme as “nuts” and pressed for the Chancellor to reconsider.
“What we need is for Rishi (Sunak) to have a good look at this and ask officials to find a way of making it work,” Mr Cameron wrote last year.
The developments are the latest in a lobbying controversy that has dogged the Conservative former prime minister in recent weeks.
Questions were mounting over his efforts to secure access for the finance company, which later collapsed putting thousands of UK steelmaking jobs at risk.
Mr Greensill was understood to have written to Mr Hancock’s office about the payment scheme in August 2019, copying in NHS England chairman Lord Prior, before the Health Secretary commissioned advice from officials.
An ally of Mr Hancock confirmed a drink took place between Mr Cameron, the Health Secretary and the Australian financier in October 2019.
Mr Greensill’s firm at the time wanted to introduce a flexible scheme to pay doctors and nurses either daily or weekly.
NHS SBS, a joint venture between the Department of Health and Social Care (DHSC) and a French IT firm, went on to announce in October last year that Earnd, a mobile app that was then a division of Greensill, would be available free-of-charge to NHS employees to access their pay.
Mr Hancock had referred Mr Greensill to work directly with the NHS rather than his department, according to the ally, who insisted the final decision to use the scheme was for local NHS employers.
“Matt acted in entirely the correct way – he updated officials on the business that was discussed, as is appropriate,” the friend said.
Mr Cameron is yet to comment publicly about the “growing scandal”, as Labour has called it.
But a source close to the former prime minister said: “David Cameron was an enthusiastic champion of Greensill’s pay product, Earnd, and met with various people to discuss its rollout across the NHS.”
A DHSC spokesman said: “The wellbeing of NHS staff is the top priority of the department and Health Secretary.
“Our approach was and is that local NHS employers are best placed to decide how different pay flexibilities fit with their overall pay and reward offer for their staff.”
Labour called for Mr Sunak to “come out of hiding” and make a statement to Parliament about the “growing scandal”, and reiterated demands for an investigation.
Shadow chief secretary to the treasury Bridget Phillipson said: “Every day brings fresh revelations about the culture of cronyism at the heart of this Conservative Government.
“Through David Cameron, Greensill looks to have had the run of Government from Number 10 down, including access to millions of pounds of public money.”
Labour MP Dame Margaret Hodge, a former chair of the Commons Public Accounts Committee, said: “We need an independent inquiry immediately. The whole scandal stinks.”