ONE of Scotland's youngest and most promising senior police officers has been demoted from superintendent to constable following a disciplinary hearing over allegations involving a woman police officer.

Iain Livingstone, 37, was working as an aide to Scotland's most senior police officer, Sir Roy Cameron, at Her Majesty's Inspectorate of Constabulary, when he was suspended in February 2003 over the claims, which arose from a drunken party at the Scottish Police College at Tulliallan.

It is understood that he plans to contest the demotion, which meant him dropping four ranks.

The former lawyer and Raith Rovers footballer had been suspended for 17 months after the WPC claimed she had been sexually assaulted during the party.

Five allegations of serious sexual assault were dismissed but, at an internal misconduct hearing, Mr Livingstone admitted less serious allegations, including being in the woman's room overnight after falling asleep.

The hearing, chaired by John McLean, Strathclyde assistant chief constable, established there had been no sexual impropriety or intent on Mr Livingstone's part.

A qualified lawyer and member of the Law society of Scotland, Mr Livingstone switched careers in 1992, joining Lothian and Borders Police.

In just 10 years, he reached the rank of superintendent and it was thought that he would reach the highest echelons of service.

Mr Livingstone was unavailable for comment yesterday. His wife, Jane, said: ''We will be taking thorough legal advice and challenging this at every level.

''As everyone knows, Iain has done nothing wrong and he is devastated at the way this has been handled. He is a man of the highest integrity with an impeccable record and we will be appealing against this decision.''

A spokeswoman for Lothian and Borders Police said: ''Internal conduct proceedings against an officer has taken place. We will not comment further on internal staff matters.''

Tom Buchan, a chief Superin tendent with Strathclyde Police and national spokesman for the Association of Police Superintendents, said: ''We can't say very much just now.

''There may well be some form of appeal and this may not be the final outcome.''

He said the association had not been involved in the case so far, but that that could change should an appeal process be started.

One officer spoke out on behalf of his colleague. He said: ''Iain has been stripped of his rank and busted to the lowest rank form simply falling asleep at a party.

''The punishment does not fit the crime and it beggars belief that they can treat an officer, who has an unblemished record and was destined for big things, like this.''