Police detectives investigating murders and violent crimes in the gay community are influenced by institutional homophobia, a report claims.

The report by the independent Lesbian Gay Bisexual Transgender Advisory Group (LGBT IAG) looked at 10 homophobic murders between 1990 and 2002, including five murders by serial killer Colin Ireland.

Four of the cases investigated remain unsolved.

The review found that many investigations were marred by lack of knowledge, reliance on stereotypes and prejudice by police.

It claims that although the situation at Scotland Yard has improved since the 1990s, more still needs to be done.

The report says: “If we borrow the terminology of the Macpherson report, historical police practice amounted to ‘institutional’ homophobia and transphobia.

“There were several investigations where we have deep reservations about the way in which the identity of the victim informed investigative decisions at the time. We also found evidence of inappropriate attitudes to the circumstances of some murders.”

The Macpherson report into the murder of black teenager Stephen Lawrence in 1997 labelled the police “institutionally racist” and led to an overhaul of police procedure, including the way ethnic minorities are recruited.

The LGBT IAG report has several recommendations which would improve the way homophobic crimes are investigated.

They suggest that better intelligence is needed to keep track of violent homophobes.

The report claims that the gay community should better warned when police consider certain areas to be dangerous, and that there is a need for more cohesion in the way the police deal with the gay community.

The report is especially damning of the way the police handled the killings of serial killer Colin Ireland.

The review finds that the investigation was “hampered by a lack of knowledge of the gay scene in London and the special culture of SM bondage.

“In particular, valuable time was lost before the police managed to recognise two common threads to the crimes. These links were established only after the death of the fourth victim.”

Police did not pick up on similarities in the way the bodies were found, and initially missed evidence that all of the victims had met Ireland in the same pub.

The report says more should have been done to warn communities, and the result was “a serious failure of policing.”

Colin Ireland eventually turned himself in to police.

Bob Hodgson, co-chairman of the review, told The Guardian: “Things were awful but now they are better. Prosecutions are improving all the time.

“But our main point today is prevention. Preventing these murders from taking place is better than having the most brilliant prosecution.”

He adds: “It is important to assess how things were and how they are now if we really hope to move forward.”

Today the five members of the research group will receive a special commendation from Scotland Yard for their findings.

Jack Gilbert, Bob Hodgson, Derek Lee, Griffith Vaughan Williams plus one other colleague were given unprecedented access to material from the Met.

Commander Dave Johnston, who is from the Met’s Specialist Crime Directorate and has overall responsibility for homicide, will be making the presentation.

Commenting on the report and the work of the members who compiled it, he said:

“Over the years the Met has developed a strong working relationship with the LGBT IAG.

“Consequently with their guidance and support we have learned from past investigations, increased our understanding and introduced a number of initiatives.

“This has resulted in increased confidence in the service we deliver to the LGBT communities of London.

“We are grateful to the members of the LGBT IAG who have given their time to help prepare this report, and the commendation is an acknowledgment of that dedication.”

He added: “Whilst the report launch marks the conclusion of this piece of work, we look forward to continuing to work in partnership with London’s LGBT communities to ensure that our service delivery meets their needs.

“All of the recommendations have been considered as ‘work in action’ over the past 4 years and where appropriate, policy and practice has been changed to ensure good practice is adopted quickly.”