Health Secretary Alex Neil demanded total transparency from NHS Lothian after The Herald revealed the chairman had plans to provide only limited details of private board meetings to Scotland's public sector watchdog, Audit Scotland.
Mr Neil immediately sent an official to inform Dr Charles Winstanley that his board must now supply officials with full minutes, agendas and background briefing papers from private board meetings dating back to 2010. Last night Dr Winstanley said he had complied with the request.
It emerged in December 2011 that NHS Lothian had manipulated waiting times by offering patients treatment at short notice in England, but if they could not attend they were marked as unavailable. The practice artificially reduced the number of people waiting for treatment, in breach of Government guarantees.
Following The Herald's front-page story yesterday, Mr Neil told MSPs: "I asked one of my senior officers to contact NHS Lothian and make it absolutely clear to them that it should already have been made clear that every element of transparency has to be fulfilled.
"There is nothing to hide. It is very important every health board is open, transparent, and totally accountable both to this parliament and to the local population. It is my view very strongly that every health board should be totally transparent in all its activities."
The disclosure went beyond a routine request from Audit Scotland to receive material from future board meetings.
The board was under pressure to provide historic material after officials confirmed that "waiting times issues would have been discussed at private board meetings" in the past.
Dr Winstanley said: "I had a visit from a senior Scottish Government official today where I made clear we had always intended to give Audit Scotland all the information they wanted.
"The request from Audit Scotland was not specific and we had believed that the minutes of the meetings would suffice.
"I can confirm we have now sent Audit Scotland minutes, agendas and all associated papers connected with our private board meetings dating back to 2010."
This week Dr Winstanley sent internal emails which revealed a plan to hand over only brief minutes from the most recent and all future private health board meetings. In the emails he told senior colleagues: "Audit Scotland are technically entitled to any information, but we would offer no more than minutes at his stage." He emphasised the "brevity" of the notes.
Although Audit Scotland had not specifically asked for material relating to private discussions on the scandal, the move would have prevented any such detail emerging.
The waiting times issue was confirmed in a report in March last year by accountants PricewaterhouseCooper (PWC), after it was ordered by Mr Neil's predecessor Nicola Sturgeon.
A subsequent inquiry, resulting from PWC's probe, uncovered a culture of bullying at NHS Lothian.
Health boards are obliged to provide full details of private board conferences to Audit Scotland and most do so automatically.
Labour health spokeswoman Jackie Baillie said: "I am pleased the Cabinet Secretary has ordered NHS Lothian to release historic minutes, agendas, briefing materials and reports from all previous 'secret' board meetings since 2010. It is unacceptable there are such meetings which discuss vital issues which are not directly related to commercially sensitive or personnel matters.
"What this shows is that there is still something fundamentally wrong within the culture of NHS Lothian. To be continuing to seek to 'play the game' when it comes to disclosing information is outrageous."
She added: "It is now clear NHS Lothian is dysfunctional and continues to fail. It is time for Alex Neil to get involved and prevent this from continuing. He needs to send in a taskforce to tackle the projected deficit of over £12 million, the ongoing treatment backlog and the cultural failings which this episode has exposed as being endemic within NHS Lothian."
A series of internal audits published last month suggested waiting times were manipulated at other health boards.
Separately, it emerged 17,360 patients were deemed unavailable for treatment for social reasons in December 2011, when the Lothians scandal was exposed. This figure halved by September last year as health boards apparently adopted different practices. Large falls were recorded in all mainland health board areas.
Audit Scotland has been conducting its own inquiry into waiting times and will publish the results on February 21.
A Government spokeswoman said Audit Scotland's request had "nothing to do with waiting times", but added NHS Lothian had provided all minutes and papers dating back to 2010.