A watchdog has claimed that Police Scotland attempted to cover up a complaint about a man being mistakenly arrested and held for several days.
The Police Investigations and Review Commissioner (Pirc) raised concerns that police recorded the complaint as a "quality of service" matter.
Senior officers claimed the way the complaint was handled was "indicative of the transparency" of its processes.
But Pirc has claimed that officers tried to keep the complaint "hidden".
The watchdog said an independent criminal investigation had led to "a number of officers" being arrested over the case, which has been passed to prosecutors.
Details of the incident emerged as the latest round in an ongoing row between Police Scotland and Pirc which has played out before Holyrood's justice committee.
Pirc commissioner Kate Frame told MSPs on the committee last week that Police Scotland had failed to report allegations of officers committing crimes to prosecutors.
She said an allegation of someone being punched in the face by an officer was recorded as "excessive force" instead of assault, and an incident where someone being "unlawfully detained" was recorded as a "quality of service" matter.
This allowed the force to investigate the allegations themselves rather than passing them to the Crown Office for an independent investigation to be carried out.
Ms Frame told MSPs that "incompetence or more sinister factors" could be responsible for the failures to properly record the allegations.
However police chiefs strongly denied this, with Assistant Chief Constable Alan Speirs saying the force "categorically rejects the assertion that any failure to report matters is due to 'sinister aspects'".
Ms Frame has now made a further written submission to the committee outlining details of several complaints, including the claim of unlawful detention.
She said the man involved had complained to police after being "unlawfully detained for a number of days", but that this had been recorded as a "quality of service" matter - and that even then his complaint was not upheld.
The man subsequently complained to Pirc, and "only then the real core of the complaint was identified as an extremely concerning and disturbing matter which required an independent criminal investigation".
Ms Frame said the watchdog's probe "resulted in a number of officers being arrested by Pirc investigators" and the matter being reported to prosecutors.
The commissioner also said the case "exemplifies both inappropriate recording of a complaint and significant inadequacies by Police Scotland in how the complaint was dealt with".
And she claimed that the case was "an illustration of Police Scotland's unwillingness to recognise serious failings, when presented with an opportunity by the complainer to address matters, and suggests an endeavour to keep those matters hidden".
ACC Speirs had accepted that police arrested a member of the public after "erroneously" identifying them as the subject of a warrant.
He said that the case "remains under consideration", and as such it "would be inappropriate to comment further".
But he claimed that "notwithstanding the differences in assessment by Police Scotland and the Pirc", the way the case was handled was "indicative of the transparency of a process which has facilitated further inquiry".
ACC Speirs said the force "works tirelessly to promote public confidence in policing", and is "fully committed" to an ongoing review of complaint handling ordered by the Scottish government.
The row was raised with Justice Secretary Humza Yousaf at Tuesday's meeting of the justice committee, and he said he would be discussing the issues with Ms Frame later in the day.