A long-awaited report into the unsolved murder of Daniel Morgan has been delayed again due to an “unnecessary” Home Office review said to compromise the authors’ independence.

Mr Morgan was killed with an axe in the car park of the Golden Lion pub in Sydenham, south-east London on March 10 1987.

Despite five police inquiries and an inquest, no-one has been brought to justice over the father-of-two’s death, with the Metropolitan Police admitting corruption had hampered the original murder investigation.

The panel examining the case had been due to publish its findings on Monday, before being told by the Home Office that no Parliamentary time could be found to allow this to happen.

Then on Monday, it announced that it wanted to review the document, expected to contain “a sizeable chapter” on police corruption, and would keep parts of it secret if it felt necessary.

The Daniel Morgan Independent Panel said it had been told a publication date would not be agreed until the Home Office reviewed the report to ensure it complied with human rights and did not compromise national security.

In a statement on Tuesday, the panel said: “This review is being sought on the basis of the Home Office ensuring the report’s compliance with the department’s obligations under the Human Rights Act 1998 and for reasons of national security.

“The Home Office advised it would make redactions if it did not consider the report complied with these obligations.

“A review of this nature has not been raised previously in the eight years since the panel was established in 2013.

“The panel believes that this last-minute requirement is unnecessary and is not consistent with the panel’s independence.”

Then home secretary Theresa May announced in 2013 that an independent panel was being set up to examine the case.

The panel’s remit was to address questions relating to the murder including police handling of the case, the role corruption played in protecting his killer, and the links between private investigators, police and journalists connected to the case.

Mr Morgan’s family said the report’s delay was a “kick in the teeth” and served only to “betray and undermine the very purpose of the panel”.

In a statement they added: “The Home Secretary’s intervention is not only unnecessary and inconsistent with the panel’s independence.

“It is an outrage which betrays her ignorance – and the ignorance of those advising her – with regard to her powers in law and the panel’s terms of reference.

“It also reveals a disturbing disregard for the public interest in safeguarding the independence of the panel and its report.

“For us as the family of Daniel Morgan, the Home Secretary’s belated and unwarranted interference in this process is simply unacceptable.”

The panel said that it had expected its report to be tabled in Parliament by the Home Secretary on Monday.

But it had been advised that the period of mourning after the Duke of Edinburgh’s death and the elections had caused a backlog of matters to be placed before Parliament.

The panel said that the Home Office had not mentioned there was a need to review the report and that it had worked with its counsel to ensure it complied with the relevant legal obligations including the Human Rights Act.

It added: “The Panel has worked closely with its counsel (a QC) and its solicitors throughout the course of its work to ensure the report complies with all the relevant legal obligations including the Human Rights Act 1998.

“A senior specialist Metropolitan Police team, subject to strict non-disclosure agreements, also reviewed all relevant parts of the near final report as part of a security check governed by an agreed protocol with the Metropolitan Police.

“This review enabled the report to be checked for any potential security risks.”

It also said that the the role of the Home Secretary was limited to reporting to Parliament on the panel’s work, receiving its report, laying it before Parliament, and responding to its findings.

It added: “The panel’s terms of reference drawn up in 2013 and a management statement agreed to by the secretary to the panel and the Home Office in 2014, outline the responsibilities of the Home Secretary in relation to the Panel’s work.

“In relation to report publication the Home Secretary’s role is limited to reporting to Parliament on the panel’s work, receiving the panel’s report and laying it before Parliament, and thereafter responding to the panel’s findings.”

The panel said it was “disappointed”, but hoped the issue could be resolved so the report can be published in May.

It added: “The panel is disappointed with this position and hopes the matter can be resolved in adequate time for its report to still be published in May while Parliament is sitting.”

A Home Office spokeswoman said the Home Secretary had an obligation to make sure the report complied with human rights and national security considerations.

She added: “This has nothing to do with the independence of the report and the Home Office is not seeking to make edits to it.

“As soon as we receive the report, we can begin those checks and agree a publication date.”