Senior police officials are reforming the national approach to investigating unexplained deaths following the inquest for victims of serial killer and rapist Stephen Port.

In January this year, a coroner’s report on the deaths of Anthony Walgate, Gabriel Kovari, Daniel Whitworth and Jack Taylor identified a “large number of very serious and very basic investigative failings” by police, including a “lack of professional curiosity” about their cases.

The report, by Sarah Munro QC, also expressed concern over how deaths are classified as “unexplained” rather than suspicious.

On Tuesday, the Metropolitan Police and the National Police Chiefs’ Council (NPCC) responded, saying they have formed four new classifications “so as to provide absolute clarity to officers responding to and investigating deaths”.

These are “expected deaths” – where there is a medical diagnosis; “unexpected death investigated and not suspicious” – where evidence shows “no third party involvement”; an “unexpected death under investigation” – where further investigation is required; and “homicide” – where it is likely there was third party involvement.

The changes will be presented to the Front Line Policing (FLP) Chief Officer Group (COG) and the Met said they aim to embed them across the force by June 30.

Ms Munro had said: “The term ‘unexplained’ as used in the current policy may distract officers from the correct and necessary approach, which is for the death to be treated as suspicious unless and until the police investigation has established that it is not.”

The coroner also expressed concern over “a lack of ownership and responsibility for the investigations of unexplained deaths” among leaders in the Met.

In response to this, the Met said they have now “agreed and set out clear guidelines detailing the responsibilities that officers of different ranks have in death investigations” leaving them “in no doubt as to their responsibilities and those of their colleagues”.

Mr Kovari’s death was classed as “unexplained but not suspicious” within five hours of his body being discovered, despite an inspector later admitting they had no idea how he had died, while Mr Whitworth’s death was also classed as non-suspicious on the day he was found, even though investigators had not properly checked that a fake suicide note found with his body was genuine.

The letter had been planted by Port, falsely claiming that Daniel had accidentally killed Gabriel, when in fact the two did not know each other and were not together on the night Mr Kovari died.

Families of the four men believed that homophobia played a part in the failings.

While Ms Munro did not make her own finding on the issue, she said she agreed with a report by the Independent Office for Police Conduct that suggested “the possibility of assumptions being made about the lifestyle of young gay men and the potential vulnerability of men cannot be ignored, and may reveal that intersectionality was present in policing in 2014/2015, and may still be”.

Digital, Culture, Media and Sport Secretary Nadine Dorries also responded to Ms Munro’s concern about the Sleepyboy website that was used by Mr Walgate in his work as an escort to arrange to meet Port.

Ms Dorries said the Online Safety Bill, which was introduced to Parliament on March 17, will “usher in a new era of accountability for the tech sector and ensure that they take more effective action to tackle criminal activity, including when their users are anonymous”.