A police watchdog has been slammed after it buried damning parts of its own report into the scale of stop and search north of the Border.

The Scottish Police Authority (SPA) had discovered that the rate of searches carried out by Police Scotland was nearly nine times higher than the rate in the New York Police Department (NYPD), but the explosive comparison never made it into its final report.

Multiple references to an academic work that was critical of the policy were also axed, deletions one MSP described as "shocking".

Stop and search, a policy strongly associated with the former Strathclyde force, was accelerated across all parts of the country following the creation of Police Scotland. Some local authority areas, such as Fife, witnessed a 400% year-on-year rise in frisks.

Other controversies have included "consensual" searches on young children and allegations that officers have been making up entries to appease their bosses. The SPA, set up to scrutinise the single force, launched a review of the policy last year and issued its findings in May.

Its report was considered to be mild by some stakeholders and did not contain many radical recommendations. However, this newspaper can reveal that the draft report painted a much more unflattering picture for Police Scotland. The draft contained a table comparing the scale of stop and search in the areas covered by Police Scotland, the Metropolitan Police in London and the NYPD. It focused on the total number of searches carried out per 10,000 people between April and December last year. For NYPD, the figure was 110.6. For Police Scotland, it was 979.6 - nearly nine times higher. However, the comparison was ditched and never made it into the SPA's final document.

The table also showed that the rate of stop and search, per 10,000 individuals, was nearly three times higher for Police Scotland than the Met. The single force figures included all statutory and non-statutory searches, whereas the Met only carries out statutory frisks.

In the final report, Police Scotland's non-statutory searches were stripped out, an omission that ensured its figures were in line with those of the Met.

The draft had concluded that stop and search was "significantly higher" in Scotland than for the Met and NYPD policing areas.

With the NYPD figures now axed, the final report stated: "The rate of statutory search in Scotland per 10,000 people is broadly similar to the stop and search rate per 10,000 people in the Metropolitan Police."

It added that "comparable" data for "similar-sized Scandinavian countries" was unavailable.

However, the final report did note that stop and search was higher in Scotland, compared to the Met, when non-statutory frisks were added. Copies of the draft were circulated to the Scottish Government and Police Scotland for comment. The SPA said that neither body queried the NYPD figures. The draft also leaned heavily on a report into stop and search by Edinburgh academic Kath Murray, whose work had been independently peer reviewed. Her report had called for stop and search on children to be reviewed and for the primary aim of the policy to be clarified. It was cited regularly in the draft SPA document, but disappeared from the final text.

The deletions have raised questions about the SPA's performance. The watchdog's job is to hold Police Scotland and its chief constable to account, but its funder is the Government.

Under previous governance arrangements, the boards that oversaw the previous legacy forces were accountable to local councils.

Alison McInnes, the Scottish Liberal Democrat justice spokeswoman, said: "We have learned that Police Scotland stopped and searched three times as many people as the Metropolitan Police last year, including thousands of children. Now it appears that unfavourable international comparisons and other damaging statistics have been buried. This is shocking."

Graeme Pearson, Labour's shadow justice spokesman, said: "The SPA is supposedly tasked by [Justice Secretary Kenny] MacAskill with providing transparency in all things policing in Scotland. These deletions from the report reflect the authority's high-handed approach to the public's right to know."

An SPA spokesperson said: "The members of the SPA Task Group felt that it was of questionable relevance to include a table which compared a small and geographically diverse country like Scotland with a highly-urbanised US mega-city like New York.

"The Task Group concluded that including a comparison with the Metropolitan Police was more relevant, and in itself clearly illustrated the apparently high use of stop and search in Scotland compared to Greater London when both statutory and non-statutory searches are considered."

A Scottish Government spokeswoman said: "It is standard practice for their draft reports to be shared with relevant partners and with the Scottish Government before they are published. The Scottish Government received a draft copy of the Stop and Search report and provided factual comments relating to accuracy."