The head of one of Scotland's largest health boards has retired, just weeks after an inquiry was launched into allegations that waiting-time figures were manipulated to meet targets.

NHS Lothian's chief executive Professor James Barbour announced yesterday he is to step down immediately.

Last month Health Secretary Nicola Sturgeon ordered an investigation into the authority's management culture after it was accused of manipulating waiting-time figures to meet targets.

It emerged more than 1200 patients had been referred to hospitals in England, but when they were declined they were omitted from a list of patients waiting more than the target of 18 weeks for treatment. Two members of staff were suspended as part of the probe.

Prof Barbour, 59, has spent 35 years in the NHS – ten of them in NHS Lothian. In 2009, he was revealed to be the fourth-highest-paid executive in NHS Scotland on a salary of £195,000.

His retirement from the health board includes a final-salary pension..

Mr Barbour said: "It has been a privilege to serve the NHS and the people of Lothian, and also to have worked with many thousands of talented and committed staff.

"The time is now right for me to do something new and different as the board embraces a new strategic direction.

"I wish all of my friends, colleagues and the staff of NHS Lothian continued success for the future."

A spokeswoman for NHS Lothian confirmed that Mr Barbour would be departing on a full pension, but said the package did not include a "golden goodbye".

She said she could not comment on what sanctions remaining members of the management team may face depending on the findings of the investigation, which has now been completed. A report is due to be submitted to the Health Secretary in May.

Labour MSP and Shadow Health Secretary, Jackie Baillie, said: "We would like to add our thanks to James Barbour for his service to NHS Lothian and wish him the best for the future.

"Scottish Labour has expressed deep concerns regarding the manipulation of waiting times in NHS Lothian but we believe this is not confined to one health board.

"We are also share the concerns expressed by the Royal College of Nursing regarding pressure on staff and it is important that the Cabinet Secretary takes action to resolve these problems as soon as possible for the benefit of patients in Lothian."

Jackson Carlaw, Scottish Conservative health spokesman, said: "This is yet another example of [people] avoiding the consequences of being held to account in the NHS. Compensation payments rocket but no-one is held to account.

"Now, in the shadow of a report which many rightly expect to be highly critical of board performance, the chief executive jumps ship so that he too can avoid any possible consequences.

Once again the public suffer – they foot the bill while others walk away from their responsibilities. This aspect of public life has become a national disgrace."

The Royal College of Nursing Scotland (RCN) called on the health board to learn from the waiting-times investigation.

Royal College of Nursing Scotland director Theresa Fyffe said: "The unhealthy culture that is currently being investigated at NHS Lothian has resulted in unacceptable pressure on staff.

"The NHS Lothian workforce has taken a lot of strain, so the Scottish Government and interim chief executive must work together to solve outstanding problems now.

"Not only this, they must put in place a clear way forward with adequate resources to address any long-term problems concerning waiting times that emerge.

"Otherwise, the already overstretched nursing workforce will be under unacceptable strain."