The BBC has obtained a confidential briefing document about the case, "Operation Submarine", prepared by the investigation's SIO (senior investigating officer).

The document is dated 12 June this year, about four weeks before the BBC contacted Police Scotland over its intention to run a story about the case.

It is described as a "high level overview" into Greer's "significant serious sexual offending".

Point 3 of the document is headlined "Identified Criminality" and details of the 2002 and 2005 investigations are listed.

It states: "Within the current vetting regime, he would not have been granted Recruitment Vetting."

The document was provided to the Scottish government and the Scottish Police Authority (SPA), the oversight body tasked with holding senior officers to account.

Yet during a public board meeting of the SPA on 30 July, a week after the BBC broke the initial story, none of the SPA board put the details of Greer's vetting issue to DCC Alan Spiers, who was there in place of Chief Constable Jo Farrell.

Board member Chris Creegan asked DCC Spiers which of Strathclyde's previous vetting arrangements were of "particular relevance to this case and Alan Greer's own history" but did not press for an answer and no details of Greer's vetting record were disclosed.

The SPA told the BBC that only the authority's chairman Alistair Hay and chief executive Chris Brown, who were both present at the meeting, received the briefing about Greer's vetting - and that it had not been shared with Creegan.

It said operational briefings were not "routinely shared" with board members.

A spokesperson for the SPA said: "Three authority members raised a number of initial questions to seek assurance about the approach being taken, the impact on public confidence - and the assertion that significant changes to vetting regulations would mean an individual such as Alan Greer, would not be able to join policing today."