Wales's chief auditor has resigned unexpectedly after an investigation into his personal conduct.

Auditor general Jeremy Colman, who has led the Wales Audit Office since it was established in 2005, stood down yesterday.

The Western Mail newspaper reports today that Colman's departure was due to the discovery of pornography on his laptop, but the Wales Audit Office (WAO) refused to confirm what was behind the auditor general's sudden departure.

A statement from the WAO said: "Jeremy Colman stood down yesterday from the office of Auditor General for Wales following an internal review around matters of personal conduct.

"We cannot elaborate any further at this moment in time."

Auditor general for Wales since the post was created in 2005, Colman's initial five-year contract was renewed for another three years in May last year.

The WAO has come under scrutiny of late, with a report published last year criticising a lack of trust within the organisation and highlighted allegations of bullying and harassment as well as accusations of nepotism in the way staff were chosen for projects.

The generally positive international peer review, led by Scotland's deputy auditor general, found that the auditor general was accessible and willing to speak to any member of staff, but there were "clearly wider issues of trust and confidence in decision-making and the wider senior management team".

It also reported a breakdown in relations between the Prospect union and management. The report was concerned that the union had "identified a perception of bullying within the Wales Audit Office although the number of actual complaints is very small".

Plaid Cymru assembly member Leanne Wood later discovered that five WAO managers were subject to disciplinary action or investigations between April 2005 and last October following complaints by staff.

All managers were given advice or asked to attend courses on workplace bullying, but Wood said there needed to be a wider investigation into the problems.