Media playback is unsupported on your device Media caption Reporter Samantha Poling has been investigating Police Scotland

Secret police documents leaked to the BBC show attempts were made to "suppress" a report containing claims of serious corruption and criticism of Police Scotland's bosses.

The report was commissioned by then-Chief Constable Sir Stephen House in 2014, a year after the new force began.

Early drafts of the confidential report show the chief constable's office wanted negative comments deleted.

A section where officers described a culture of fear was also removed.

The BBC also obtained an email from within Police Scotland which showed that, as well as attempting to edit the report, Sir Stephen House - who left his post in 2015 - indicated that he was prepared to "suppress" it altogether, unless a specific word was changed.

Police Scotland said "significant changes have been implemented" since the report was written.

However, opposition parties said the revelations raised serious questions and urged Justice Secretary Michael Matheson to come before MSPs and address the matter.

The issue will be raised by Tory MSP Liam Kerr during topical questions, watch live at Holyrood Live from 2pm.

Image caption Sir Stephen stood down from his position at Police Scotland in 2015

A former member of the Scottish Police Authority (SPA), which is the body tasked with overseeing standards at Police Scotland, said changes to the report were concerning.

Moi Ali, who resigned from the SPA board last year after a row over transparency at the organisation, told the BBC: "I am shocked that the chief constable's office should see fit to try to pretty much obliterate any kind of criticism whatsoever because if this is what the report found, then this is what it found and this is what should have been published."

Five previous drafts of the report in total were leaked to the BBC. Internal memos within the first version show details of misconduct and corrupt behaviour by officers.

Image caption Moi Ali said criticism was pretty much obliterated from the report

In one memo, a range of conduct issues which were found in one unit in Tayside are listed.

They include officers conducting unauthorised surveillance, threatening and intimidating witnesses, unlawfully detaining suspects, colluding while compiling statements and failing to reveal evidence.

Another memo describes how two detectives were captured on a police station's CCTV with a murder suspect.

The officers stood either side of him and began to "informally" interview him, "assert his guilt" and all "without affording him a common law caution".

Both those memos are gone from the final version of the report.

Conduct committee

Moi Ali told the BBC that the details of misconduct and corrupt behaviour detailed in the internal memos was "concerning".

"I was a member of the complaints and conduct committee which clearly this concerns," she said.

"Allegations of this kind of behaviour have not to my knowledge been put to the board."

In total, 334 officers and staff at Police Scotland were asked to give their views on the force and its management anonymously for the report which was entitled 'Police Scotland Quality Assurance Review'.

Their responses raised a number of serious issues, from apparently routine misconduct and rule-breaking, to strong criticism of the force's leadership and direction under the then-chief constable, Sir Stephen House.

Another issue which is raised repeatedly in a series of damning quotes from officers is that of performance targets and the lengths that are gone to in order to meet them.

One says that "officers on the beat are almost bullied into producing returns to satisfy management," and another that "officers may feel under pressure to fake stop-search returns to boost the figures".

Other testimony suggests that the reporting and recording of crime statistics were manipulated in the early days of the force as a result of the pressure officers felt they were being placed under.

One tells the review team that "in some instances officers felt pressure to charge a person even when there is not enough evidence in order to meet targets," while another says they are aware of the use of "questionable methods such as the re-categorisation of crime to meet targets".

Yet, as with the memos detailing instances of specific misconduct and corrupt practices, these quotes are also missing from the final version of the report.

Image caption The word "fear" was removed from a section of the report

One word that is raised by numerous officers in the original version of the report is "fear".

They say that "people are driven by fear", that there is a fear of being criticised, a fear of missing targets and a "fear of a backlash from the force executive".

However, despite the word 'fear' appearing 10 times across two paragraphs in the original report, that word is removed from that section of the final report entirely.

Image caption Brian Barbour said it was "shocking" to leave out the testimony of the officers

Brian Barbour also served on the board of the Scottish Police Authority (SPA) until 2017, when he too resigned, citing interference by the Scottish government in the SPA's work.

He told the BBC that the testimony from the officers and its omission from the final report were "shocking".

"I understand things go through a process but I would never have envisaged asking people their views and then misrepresenting them," he said.

Image caption A section on "expressions of fear and anxiety" was completely changed

The leaked documents also show that attempts were made by the then chief constable's office to have some of the words and conclusions of the original report changed.

In the fourth version of the report obtained by the BBC, Sir Stephen House's handwriting can be seen, as well as the writing of another official.

At one section entitled "Expressions of Fear and Anxiety," a pen scores out these words and replaces them with the phrase "Culture and Communication" and this change is included in the final report.

Barbour said: "To take a culture of fear and translate it into a culture of communications isn't something that carries integrity."

Changes are also made to the tense in a series of sentences, for example, the sentence which read "communication in Police Scotland requires urgent and significant improvement" is changed to "communication in Police Scotland required urgent and significant improvement."

Less transparent

The BBC showed the different versions of the report to anti-corruption organisation Transparency International.

Its UK director Dr Robert Barrington said: "What you have over the course of the drafting is something that becomes steadily less transparent, less challenging."

"When you have a culture that doesn't operate transparently and doesn't encourage people to speak out those are actually the conditions within which corruption can thrive rather than in which it's really exposed."

The BBC has also obtained an email from within Police Scotland which shows that, as well as attempting to edit the report, Sir Stephen House indicated that he was prepared to "suppress" it altogether, unless a specific word was changed.

The email reads: "The chief will not allow the report to be tabled unless this is amended."

It goes on to say that the word in question is in the sentence: "It is clear that much anxiety and uncertainty as to what was expected remains among staff at operational unit level."

The email continues: "The proposal is to change the word remains to 'existed'."

"Apparently this was almost a 'last straw' from the chief and there is a danger that he will suppress this unless amended."

The email then states that to change the word "to existed, doesn't state that these feelings weren't discovered by the review, it just simply doesn't mention that these feelings may still exist."

"A play on words I know."

Brian Barbour criticised the editing of the report: "It's been changed and diluted and the message that's come out isn't the view of those who expressed it in the first place. It makes me feel as though I've been part of an organisation that has let people down."

Sir Stephen House said he did not wish to comment on the BBC's investigation.

Image caption The current chief constable has acknowledged the challenges of the early days of the force

In a statement Police Scotland said "significant changes have been implemented" since the report was written in 2014 and that "last year DCC Iain Livingstone, the interim Chief Constable, led the development of and launched a wellbeing strategy for all officers and staff."

It added: "DCC Livingstone has already acknowledged that in the early days of Police Scotland process was put ahead of people at a time of challenge and difficulty for everyone involved."

The BBC asked for the final version of the Quality Assurance Review report from 2014 in a Freedom of Information request.

Police Scotland refused this saying to release the report would "inhibit substantially the free and frank exchange of views" within the force.

A Scottish government spokesman said: "The Scottish Police Authority are seeking assurances from Police Scotland that matters raised were dealt with at the time. Clearly any specific allegations of misconduct should be dealt with by the appropriate authorities.

"The current leadership of Police Scotland and the Scottish Police Authority have made very clear commitments to improvement, including recent changes to how conduct and complaints issues are handled, while officers and support staff continue to work hard to keep our communities safe, having contributed to a fall of over 38% in recorded crime over the last decade.

"This is supported by the Scottish government providing real terms protection to the police resource budget and a commitment to protecting the police resource budget - a boost of £100m by 2021."

BBC Scotland investigates: A Force in Crisis will be shown on BBC One Scotland on Monday 30 April at 20:30.