Whitehall’s independent watchdog has found “no evidence” that ministers or officials considered potential conflicts of interest before giving the disgraced financier Lex Greensill government contracts just months after he had left a job as a No 10 adviser.

The National Audit Office said Greensill left a job as an adviser to David Cameron, then the prime minister, in 2017. Eight months later, his firm was involved in a bid for a large public sector contract.

A report released on Friday said the two projects involving Greensill Capital – an early-payment scheme for pharmacies and a salary advance facility for employees of NHS trusts – did not receive the expected uptake and offered no material benefits to the NHS.

Greensill Capital collapsed in March 2021, triggering a series of investigations examining the financier’s close links with the government and Cameron’s lobbying activities.

Meg Hillier, chair of the Commons public accounts committee, said: “This report provides further information on the role of Lex Greensill and Greensill Capital in providing government services.

“It raises yet more questions over the government’s ability to prevent conflicts of interest and the independence of advice it receives.

“The consequences once again fall squarely on the taxpayer, with increasing risks to value for money and promised savings vanishing into thin air.”

Auditors said Greensill advised ministers and officials on supply chain finance in various roles from 2012 to 2017.

He attended a “key meeting” in March 2017, his final month advising the government, which considered the setting up of a framework agreement for supply chain finance.

By November 2017, Greensill Capital was a subcontractor to a firm called Taulia as part of a bid to provide supply chain finance to the public sector, ultimately landing the pharmacies deal.

The scheme allowed chemists to be paid for dispensing prescriptions earlier than they would have under NHS systems.

“We have seen no evidence that there was any discussion of a potential conflict of interest in relation to Greensill Capital being appointed as a subcontractor for supply chain finance services, about which Lex Greensill had earlier provided advice,” the NAO said.

The report found there is “no evidence that the predicted benefits and savings” from the pharmacies deal were ever realised.

The collapse of Greensill resulted in the government stepping in to pay pharmacies for predicted dispensing activity, although the cost to taxpayers was “minimal”.

Greensill’s salary advance scheme for NHS trust workers – Earnd – resulted only in “limited employee uptake”, the NAO said.

After the firm failed, some NHS trusts switched to a paid-for salary advance scheme, rather than the free version that had been offered by Greensill.

A government review by the corporate lawyer Nigel Boardman into the Greensill scandal called for a new code of conduct and greater clarity about who is funding lobbying in Whitehall.

The extent of the lobbying efforts, which included Cameron contacting the chancellor, Rishi Sunak, on his private mobile phone, were initially revealed by media reports rather than official records. The scandal raised concerns over the way private businesses have been able to hire and use former officials to try to gain preferential access to government contracts.

Boardman recommended in his review that the “transparency of lobbyists be strengthened”, including by “requiring lobbyists to disclose the ultimate person paying for, or benefiting from, their lobbying activity”.