A deputy chief constable who was in charge of the Unit that illegally spied on journalists' sources is to retire within months.

Neil Richardson, who was accused of lying about the scandal by one of his own detectives last week, will leave Police Scotland after high level talks with the chief constable.

Richardson's term as a DCC was due to expire in November and Police Scotland previously said that chief constable Phil Gormley had spoken to all his deputies about their future.

The retiral follows claims by murder detective David Moran, who was unlawfully targeted by the single force, that DCC Neil Richardson may have “made up” some of the evidence he gave to a Holyrood committee examining the scandal.

It has been claimed detectives were ordered to acquire phone data from suspected sources to discover how information was obtained about the failed £4million inquiry into Emma Caldwell’s unsolved murder nearly 11 years ago.

The revelations triggered a probe by MSPs on the Holyrood Justice Committee, which heard evidence from Mr Richardson, who has responsibility for the Counter Corruption Unit.

Mr Moran, an officer with over 30 years’ service, revealed himself to be one of the four individuals targeted by his own force that hoped to discover police officers that may be leaking details of the unsolved murder inquiry.

In a letter to the Committee, which is on the Holyrood website, he said: “I have subsequently been able to piece together what I believe to be a fairly accurate, if not complete, picture of the illegal course of conduct against me.”

HeraldScotland: Deputy Chief Constable Neil Richardson (left)

Mr Moran wrote that the breaches had been wilful, rather than just reckless: “I do not believe the actions carried out by Police Scotland to have been reckless as determined by IOCCO (Interception of Communications Commissioner's Office) and I do not believe they had full possession of the facts when reaching that conclusion.”

“Consequently I have made a complaint to the Police and the Procurator Fiscal through my solicitor Peter Watson that I believe I am a victim of a crime and that the course of conduct followed was wilful and therefore a criminal action.”

Mr Richardson is the second highest-ranking officer in the country after Chief Constable Phil Gormley.

Richardson's 30 year policing career began in 1985 when he joined the then Lothian and Borders force.

He became Stephen House's deputy at Strathclyde Police in 2008 before being appointed the single force's number two in November 2012.

Richardson was shortlisted last year to take over as the new chief constable, but his responsbility for the rogue Counter Corruption Unit (CCU) damaged his chances.

Commenting on his decision, DCC Richardson said “I am extremely proud of what we have achieved in Police Scotland and privileged to have been able to play a part in what has been an historic change to policing in this country.”

Mr Gormley is in discussion with the Scottish Police Authority and a selection process to identify DCC Richardson’s replacement will start shortly

The Chief Constable said: “Neil has served the communities of Scotland for over 30 years and has been a pivotal figure in the reform of policing and the creation of the single national Service. His contribution has been outstanding and that has been recognised with the award of the OBE and QPM.”

SPA Chairman Andrew Flanagan said “Neil has been a leading figure in Scottish policing for many years and I wish him every success as his future develops beyond policing. He has been an outstanding public servant and leader.”