Former union retreat Currawong, at Pittwater.

Former union retreat Currawong, at Pittwater. Photo: Paul Miller

Labor leader John Robertson displayed an ''error of judgment'' by failing to report an attempted $3 million bribe from late businessman Michael McGurk, an inquiry has found, potentially reigniting questions over his leadership.

The parliamentary inquiry into the sale of the former union retreat Currawong at Pittwater found that the offer, made when Mr Robertson was head of Unions NSW, should have been reported to police and his own organisation.

It would also have been ''reasonable and prudent'' for Mr Robertson to have disclosed the offer later, when he was a Labor minister, the report said.

Opposition Leader John Robertson failed to report a $3 million bribe offer made by Michael McGurk.

Opposition Leader John Robertson failed to report a $3 million bribe offer made by Michael McGurk. Photo: Dean Osland

The upper house inquiry was chaired by Shooters and Fishers Party MP Robert Brown, with Greens MP John Kaye as deputy. It also comprised three government MPs, who believed the findings did not go far enough, and two Labor MPs, who described the inquiry as ''a political stunt''.

NSW Treasurer Andrew Constance said the findings showed Mr Robertson was "untrustworthy" but Mr Robertson said the matter ocurred "almost a decade ago" and he received no benefit.

The inquiry was triggered by Mr Robertson’s revelation last year that he was offered a bribe in 2006 by standover man Mr McGurk, who was later shot dead. Mr McGurk wanted to buy Currawong for $30 million.

Mr Robertson rejected the bribe but did not refer it to authorities, saying later he had satisfactorily ''shut it down''. The NSW Crimes Act requires anyone with knowledge of an indictable offence to report it to police.

In evidence, Mr Robertson said in hindsight that ''if I had my time over again I would err on the side of caution and report it''.

The committee also found it was ''inappropriate’’ that Mr Robertson met with Mr McGurk alone in March 2006, when the attempted bribe took place, and that he ''should have appreciated the potential repercussions'' of the dubious meeting.

It said there was no evidence to suggest Mr Robertson ''received any financial gain or reward'' from the offer, but he displayed an error of judgment in failing to inform police and Unions NSW.

The report said Mr Robertson also failed to disclose the conversation once he was a Labor minister, during parliamentary deliberations in 2009. A bill being considered would have allowed the Independent Commission Against Corruption to hear audio recordings of conversations involving Mr McGurk which allegedly implicated senior NSW Labor identities.

Mr Robertson voted for the bill, which passed. ICAC later found allegations over the tapes were without substance.

The parliamentary inquiry examined whether Mr Robertson should have declared a conflict of interest if there was a chance he was recorded or mentioned in the tapes.

Mr Robertson did not believe he was on the tapes, and argued ''if I had been worried and I had a conflict, I would have voted completely the opposite way''.

The inquiry found Mr Robertson did not contravene any parliamentary code of conduct. But it said the ''high standards of integrity'' required of ministers meant it would have been ''reasonable and prudent'' to have disclosed the bribe offer to then-premier Nathan Rees and to Parliament.

It recommended conflict of interest provisions in the MP code of conduct be examined, with a view to including current or previous business dealings ''which have the potential to unduly influence a member’s actions''.

Mr Robertson said he has ''always supported greater transparency'' for MPs and ministers.