The probe - the outcome of which was announced on Monday - focused on the actions of officers involved in a 2015 inquiry into claims that information about the investigation into the murder of Emma Caldwell in 2005 was leaked to the media.
It was carried out by Assistant Chief Constable Mark Hamilton, of the Police Service of Northern Ireland (PSNI), at the request of Police Scotland Deputy Chief Constable Rose Fitzpatrick.
The appointment of the PSNI to undertake a misconduct investigation followed recommendations made by Durham Constabulary which, again at the request of Police Scotland, made inquiries into a number of non-criminal complaints relating to matters connected to a breach of communications data protocols and guidance identified by the Interception of Communications Commissioner’s Office (IOCCO) in June 2015.
The probe found that there was no misconduct on the part of any officer.
DCC Fitzpatrick said she endorsed that finding and has determined that there was no misconduct by any of the seven officers investigated.
However, police bosses said the probe had resulted in “significant organisational learning”.
Duty restrictions on all of the officers have been removed and they will return to operational roles. All of the officers have now been informed of the outcome.
Police chiefs also stressed that none of the seven officers were at any time involved in the investigation into the murder of Emma Caldwell.
DCC Fitzpatrick said: “I have reviewed the findings of the enquiry by ACC Hamilton and have determined that there was no misconduct on the part of any of the officers who were investigated.
“Police Scotland acknowledged the IOCCO findings. We accepted that the service did not adhere to new guidelines covering access to communications data and that standards fell below those required.
“Following the IOCCO ruling, Police Scotland asked Durham Constabulary to investigate complaints from four people who were affected by that failure and I subsequently apologised to each of them wholeheartedly and unreservedly for what had happened and for the impact on them personally.
“It is important to recognise that since this happened in 2015, a significant amount of work has already taken place in Police Scotland to ensure such failings are not repeated.
“A detailed action plan, overseen by Her Majesty’s Inspectorate of Constabulary in Scotland (HMICS), was put in place as soon as these matters were highlighted by IOCCO and we will now work to produce, publish and implement an organisational learning report based on the findings of the Durham and PSNI reports.”
DCC Fitzpatrick added: “We have already implemented 35 of 39 recommendations from an HMICS review of the former Counter Corruption Unit, and the remainder will now be discharged early this year.
“This has clearly been a long and complicated process, but Police Scotland has continued to focus on the on-going investigation into Emma Caldwell’s murder. We will do everything we can to bring her killer to justice.”