David Cameron was paid a total of £7.2m over a number of years by failed supply chain finance firm Greensill Capital before it went bust in March.
Documents, uncovered by the BBC Panorama, have revealed this included £3.3m he received after selling his Greensill share options in 2019.
Cameron has said in the past that he was paid a “generous amount” by the firm, but would not divulge the exact sums involved.
Greensill Capital collapsed earlier this year, after its main insurer pulled its coverage and refused to cover the loans the firm was making, leading to thousands of job losses.
The former Prime Minister was a senior adviser for Greensill and became embroiled in a scandal this year when it was revealed he had aggressively lobbied senior ministers on behalf of the firm.
Cameron sent dozens of emails, texts and WhatsApps to senior civil servants in the Treasury and Bank of England as well as cabinet ministers to lobby on behalf of Greensill Capital in April last year.
This included to chancellor Rishi Sunak and Cabinet Office minister Michael Gove.
He was trying to get the firm to join the Covid Corporate Financing Facility (CCFF), which saw the Bank of England buy billions of pounds worth of bonds in investment grade companies in a bid to increase liquidity during the pandemic.
Cameron was unsuccessful in his attempts.
A letter from Greensill Capital to Cameron showed he was offered £3.3m for the tranche of shares in 2019, while it is also understood that he was paid a £720,000 annual salary.
The BBC reports that he was also given a £504,000 bonus in 2019 in addition to his base salary.
A spokesperson for the Prime Minister said that Cameron’s wages were a private matter.
The spokesperson said: “He acted in good faith at all times and there was no wrongdoing in any of the actions he took.”
Boris Johnson sanctioned a probe into Cameron’s lobbying efforts, which was conducted by City lawyer Nigel Boardman.
The report critiqued the government’s handling of the UK’s lobbying system, which it said gives access to a “privileged few” like former Prime Minister and Greensill Capital adviser David Cameron.
However, Boardman also said “the current [lobbying] system and those operating within it worked well” as evidenced by the failure of Cameron’s lobbying efforts.
Boardman said Cameron often “understated the nature of his relationship with Greensill Capital” when lobbying government figures to try and get a government Covid bailout for the former supply chain finance firm.
Boardman said the fact Greensill Capital was turned down by the Treasury for involvement in the Covid CCFF showed that the lobbying system was working properly.