Two former bosses of the Western Isles NHS board lied to the Scottish Parliament's audit committee, according to evidence uncovered by BBC Scotland.
The audit committee is investigating the board's finances
Former chief executive Dick Manson and chairman David Currie told MSPs they had not seen a report into failings in financial reporting at the board.
However, both men attended a private meeting of the board called to discuss that specific report.
Mr Manson and Mr Currie denied they deliberately lied to the committee.
Mr Currie said he was appalled the BBC could suggest that he had.
In a statement, the former chairman said: "I categorically refute allegations made on BBC Radio Scotland and the BBC website that I deliberately lied to the Scottish Parliament audit committee regarding a report on serious financial failings of the board.
"It has been confirmed by several of my former colleagues that there may have been a failure to recollect that particular report."
Mr Manson said: "I did not lie to the committee. I told the committee I couldn't recall this report and responded to further questions still saying I couldn't really recall it."
Health Secretary Nicola Sturgeon told BBC Radio Scotland's Good Morning Scotland programme the matter was "deeply concerning".
She said: "It is for the audit committee of the Scottish Parliament to decide what further action it wants to take."
The audit committee has been probing serious overspends by the organisation. Evidence to the committee is not given under oath.
Mr Manson and Mr Currie were called to give evidence at a meeting of the committee on Wednesday.
The former chief executive was asked repeatedly by MSPs if he had seen the report into serious failings into financial reporting.
Four times Mr Manson replied he had not. Mr Currie also denied seeing the report.
But other board members have confirmed that both men attended a private meeting called to discuss that very report.
Meanwhile, a confidential account of the meeting written by the chairman confirms that Mr Manson distributed copies of the report and answered questions regarding its contents.
Earlier this month, the health board's problems controlling its finances were further highlighted after it emerged projected savings were counted twice.
The error was made prior to a Scottish Executive-appointed managerial support team being installed at NHS Western Isles in 2006.
A letter by Dr Kevin Woods, the chief executive of the NHS in Scotland, said the board's budget projections for 2005 to 2006 were completely wrong.
This was partly because planned savings were miscalculated.
Dr Woods said the board also failed to create a finance committee that it had promised to put in place in an effort to control the situation.
In 2006, the then Health Minister Andy Kerr appointed a new interim chairman to the board and sent in a managerial support team.
This was amid accusations of mismanagement and following a vote of no confidence in the board's chief executive, chairman and medical director by staff.