A report into the murder of a private investigator 30 years ago will be published next month, the Home Office has said, after being accused of trying to censor it as part of a “cover up”. An inquiry has been under way for eight years into the 1987 killing of Daniel Morgan, who was found in a south London pub car park with an axe embedded in his head. The panel had completed its work and planned to publish its findings this week, but the home secretary, Priti Patel, said she needed to check the report before it was published – citing “national security” reasons. This prompted fury from Morgan’s family and the panel chair, Nuala O’Loan, who had been looking into claims that the murderers were shielded by state corruption. No one has ever been convicted of Morgan’s murder. On Friday, the panel confirmed the report would be published on 15 June, after an agreement was reached for a “small team” from the Home Office to be permitted to read the report in advance of publication. The panel’s terms of reference included “police involvement in the murder; the role played by police corruption in protecting those responsible for the murder … and the failure to confront that corruption”. It was also tasked with examining “the incidence of connections between private investigators, police officers and journalists at the former News of the World and other parts of the media, and alleged corruption involved in the linkages between them.” The panel said on 18 May it had been “informed” that a publication date for its findings “will not be agreed until the home secretary and Home Office officials and lawyers have reviewed the contents”. Highlighting what it thought was the strange nature of the Home Office’s decision, the panel added: “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.” Earlier this week, the Labour MP Chris Bryant also raised concerns in parliament that “people with very close friends in News International might want to delay or even prevent this publication” and asked: “Won’t people conclude that the cover-up is still going on?” When news of the report’s new publication date was confirmed, Morgan’s family released a statement saying the agreement meant Patel had to “submit to conditions that are designed to safeguard the integrity and the independence” of the report. They added: “We understand further that, in the unlikely event of the home secretary seeking to redact anything in the panel’s report, any such redaction will be highlighted on the face of the published report, and the redacted content will be shared with us. “We hope that the home secretary does not seek to go behind that agreement, and we call on her to ensure that she co-operates with the panel to allow the publication of the report to proceed as announced without any further delay”. A Home Office spokesperson said their “sympathies remain” with Morgan’s family, and that Patel would “meet her responsibilities to ensure publication complies with human rights and national security considerations”. It is understood the 15 June publication date is only provisional, and subject to officials from the Home Office completing checks in time.