Tony Blair has received cash from a South Korean oil firm in a deal kept secret until the business appointments watchdog intervened, the Guardian has learned.
After 20 months of secrecy, the former prime minister has now been overruled by the chairman of the advisory committee on business appointments, the former Tory cabinet minister Ian Lang.
Lang this week ordered publication of Blair's deal with UI Energy Corporation, which has extensive oil interests in the US and in Iraq.
Blair repeatedly claimed to the committee, which assesses jobs taken up by former ministers, that the existence of the deal had to be kept secret at the request of the South Koreans, because of "market sensitivities".
According to a committee spokesman, Blair's claims of the need for secrecy were first made in July 2008, when the committee agreed to break its normal rules, and postpone publication for three months.
Blair's office went back to the committee in October of that year and asked for a further six months. They promised to let the committee know as soon as the "market sensitivity" had passed.
Committee sources said they heard nothing further and had to "chase" Blair. This culminated in a formal letter from the committee last November. Blair's office responded last month, claiming the deal was still too sensitive to reveal.
Lang, who is understood to have reviewed the files, told Blair he saw no reason to keep the deal secret any longer.
The committee website now publishes a statement identifying Blair's job as "advice to a consortium of investors led by the UI Energy Corporation (Publication delayed due to market sensitivities)".
The committee also detailed on its website a similarly unpublished Blair deal with the ruling family in Kuwait. He has been in their pay since December 2007, with the task of producing a general report on the oil state's future over the next 30 years, at a reported £1m fee.
Asked about the Korean deal, his spokesman said: "Mr Blair gave a one-off piece of advice in respect of a project for UI Energy in August 2008. He sought, and received, approval from the advisory committee on business appointments before undertaking this project."
He added: "UI Energy requested of the committee that they delay public announcement for reasons of market sensitivity, which the committee agreed to do."
He would not say what the advice was about, or how much Blair was paid.
The Korean firm is normally frank to the point of boastfulness about its hiring of former top politicians. It says on its website: "This is a strong competitive edge that UI Energy Corporation has over other companies."
The former Australian prime minister Bob Hawke has been one of its paid advisers. It also lists US politicians on its payroll, saying: "Congressman Stephen J Solarz, the former secretary of defence Frank C Carlucci, the former ambassador to Egypt Nicholas A Veliotes, and US commander for the Middle East General John P Abizaid exercise their network and political influence to promote UI Energy on the development of oil fields in Iraq where the USA governs."
Blair's office denies that the help given to UI Energy was linked to Iraq, where the Korean firm's consortium at the time had just struck oil in a controversial deal with autonomous Kurdistan, to the displeasure of the central Iraqi regime.
It said: "The project had nothing to do with Iraq".
Blair, who set up a commercial consultancy firm, Tony Blair Associates, following the Korea and Kuwait deals, has been secretive in the past about his money-making schemes.
A Guardian investigation last year found that he had put his multimillion-pound income through an obscure partnership structure called Windrush Ventures, which enabled him to avoid publishing normal company accounts.
