A CONTROVERSIAL Police Scotland internal investigation unit is to be wound down, it has been reported.

Unnamed senior officers told the Sunday Mail that the Counter Corruption Unit will begin to be shut down amid mounting concern about heavy-handed tactics and over-the-top inquiries.

The move comes after new chief constable Phil Gormley arrived at Police Scotland as is understood to be linked to his desire to get his house in order.

The CCU has been mired in controversy since watchdogs accused them of “recklessly” launching an unauthorised hunt for officers who leaked information about the Emma Caldwell murder inquiry.

The force unlawfully tried to find out whether four serving and retired police officers passed information to a newspaper about the original investigation into the murder of the sex worker in South Lanarkshire 10 years ago.

They targeted two serving officers and two former officers but were later found to have obtained phone, and possibly email, data without a judge’s authority.

The revelations triggered a probe by MSPs on the Holyrood Justice Committee.

Much of the unit’s role and responsibility for probing allegations of wrongdoing by officers to independent investigators is expected to be handed to independent investigators.

The Scottish Police Authority asked Her Majesty’s Inspectorate of Constabulary in Scotland to investigate the CCU after it was revealed officers had breached guidelines demanding a judge’s approval before they take action to discover journalists’ sources.

The CCU’s targets have lodged criminal complaints after it emerged senior officers were warned the operation would breach the rules but pressed on anyway.

HMICS investigator Stephen Whitelock is leading the inquiry despite being in joint charge of Strathclyde CID between 2005 and 2008, which covered the Emma Caldwell murder inquiry. His report is due to be completed soon.

The Sunday Mail reported that the CCU's duties will be handed to the Police Investigations & Review Commissioner.

Labour’s justice spokesman Graham Pearson said: “This unit was set up to tackle major corruption in the police.

“By carrying out long investigations into officers accused of minor data protection breaches, it has created an impression of injustice among rank and file officers which has caused problems with morale.

“Phil Gormley is clearly setting his soldiers in the right order. I carried out a review of policing in Scotland in November and recommended exactly this move.”

Earlier this month it emerged that a deputy chief constable who was in charge of the unit is to retire within months.

Neil Richardson, who was accused of lying about the scandal by one of his own detectives, 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 the Holyrood committee examining the scandal.

However, Police Scotland said: “There is no imminent closure of this unit.”