A criminal investigation has been launched into the Ministry of Justice after a report leaked to BuzzFeed News suggested the department buried damning research into people defending themselves in court.

The decision was taken by the Information Commissioner’s Office following formal complaints from BuzzFeed News and others that the government had concealed the existence of a 36-page internal report that contained explosive testimony from senior judges about the impact on the justice system of unrepresented people in crown court.

The research was commissioned by the government to review the impact of cuts to legal aid made in the 2012 Legal Aid, Sentencing and Punishment of Offenders Act (LASPO) and was based on in-depth interviews with 15 crown court judges and six prosecutors.

The Information Commissioner compelled the MoJ to release a report following Freedom of Information requests from BuzzFeed News and others. Yet what was released by the MoJ was clearly marked “summary” and was just six pages long. The following week the full 36-page report – something the press office previously said did not exist – was leaked to BuzzFeed News.

Under the Freedom of Information Act it is a criminal offence to alter, block, destroy, or conceal information whose release has been compelled by the ICO. The penalty is a fine, though in theory senior officials could face jail for contempt of court after failing to comply with an ICO decision notice.

BuzzFeed News understands the criminal case was opened earlier this week and work began on it yesterday. A criminal investigating officer within the ICO will now gather evidence and is expected to interview staff at the MoJ.

The MoJ had initially turned down FOI requests for the report in spring 2017, insisting the politically embarrassing research needed to be kept under wraps because it related “to the formulation or development of government policy”.

The six-page summary it eventually released to the Information Commissioner was dated August 2016 and marked “unpublished summary as of 27 April 2018”. The 36-page report leaked to BuzzFeed News is dated February 2016 and includes damning quotes from crown court judges about the challenges created by people defending themselves without a lawyer.

Shadow justice minister Richard Burgon said: “These are very serious allegations against the Ministry of Justice. I will be raising this in parliament at the earliest opportunity.

“Regardless of the embarrassment it causes, the government should now publish the report in full and should stop trying to cover up the true scale of the damage that its cuts are causing to access to justice.”

The MoJ repeatedly insisted that the six pages were the report in its entirety, despite it being labelled a summary and containing no direct testimony or data. An MoJ press officer said that any edits from the original draft were minor corrections to spelling or grammar.

Penelope Gibbs, director of the charity Transform Justice, was one of several parties to make an FOI request for the report. Her discovery that the internal research had been commissioned prompted a question in the House of Lords in March 2017, leading to FOI requests from BuzzFeed News and others.

Gibbs said: “The behaviour of the Ministry of Justice makes a mockery of FOI. If I had not known they were doing research on unrepresented defendants in the Crown Court, this important report would have been kept completely secret. How can a department espouse the importance of open justice, without being open about the information they hold?"

The Conservative chair of the justice select committee told BuzzFeed News earlier this week the situation was “very concerning” and that it was “imperative that there’s maximum transparency on the way government decisions are taken”.

The MoJ has not yet given a comment on the opening of the investigation, but responding to an earlier story on the subject, a spokesperson said: “As we have repeatedly made clear, the 36-page version of the report was an early draft and clearly marked as such.

“Research reports must be of the highest standard and parts of earlier drafts were deemed by researchers to be of insufficient quality.

“Any request for an earlier draft would have been considered in the normal way.”

They added: “Last year we spent £1.6bn on legal aid, just over a fifth of the Ministry of Justice’s budget – and we are conducting an evidence-based review of the changes made under LASPO which will report back later this year.”

The spokesperson also said: “Both the draft and final versions of the report note that legal aid for Crown Court cases did not change substantially under our legal aid reforms and the number of unrepresented defendants remained broadly stable.”

However, last year more than 6,000 people faced criminal charges without a lawyer or had unknown representation at their first hearing in crown court – 7% of all defendants. In 2013 this proportion was 5%.

The research itself said: “the majority of interviewees believed that the numbers of unrepresented defendants had risen since legal aid changes, although the rise was seen as small.”

Though the cuts introduced by LASPO largely affected civil law, the research suggests one “significant change” to criminal legal aid appears to have prompted a rise in people defending themselves without a lawyer.

Since January 2014, defendants whose disposable annual income was £37,500 or more were not eligible for criminal legal aid. Before LASPO there was no upper income threshold in crown court cases and the research says the change created a “risk of an increase in unrepresented defendants in the crown court.”

An ICO spokesperson said: “We are making enquiries into a complaint about an FOI request in relation to the Ministry of Justice.”

