Detectives who interviewed Barking serial killer Stephen Port after his first murder failed to flag up a "significant" earlier incident, an inquest has heard.

Port, who killed Anthony Walgate after meeting him on June 17, 2014, gave a series of differing accounts to detectives when interviewed in the days after the fashion student’s death.

In the second of the interviews, he was questioned by Det Con Jolyon Holt and Judith Levoir 10 days later about what happened that night.

Port’s said he arranged to meet Mr Walgate, who would occasionally work as an escort, for an overnight stay at his flat in Barking for £800.

He claimed Mr Walgate had taken drugs and become ill, causing Port to panic and move his body outside the building in case it looked "suspicious just like last time”.

When pushed about what he meant, the detectives were expecting him to outline details of an earlier allegation from 2012 that he had drugged and raped a man on New Year’s Eve.

But instead Port told them he had been “helping” a friend who had become unwell at Barking Station and was going through his bag looking for his phone to get assistance when he was stopped by police officers.

Jurors have already been told that Det Ch Insp Chris Jones from the Met Police specialist homicide command would have taken over the investigation into Mr Walgate’s death had he known about the incident.

Counsel to the inquest Andrew O’Connor told Ms Levoir the "significance of this incident must have been obvious”.

Giving evidence on Monday (October 18), she told the jury: “It was just another line of inquiry that needed looking into in respect of what he’d said in interview.”

The inquest heard that Ms Levoir did not check the police database for details of the incident or ask another officer to do so, despite realising that it was significant.

She put crosses next to the incident in her handwritten notes, which were passed onto senior officers, but did not take further action to draw their attention to it, the court heard.

The initial investigation into Mr Walgate’s death led only to Port being charged with perverting the course of justice.

He went on to murder three more men in the same way, with fatal overdoses of the drug GHB.

Two were in 2014 while he was on bail for perverting the course of justice, and the fourth after he had served three months in prison for the offence.

Port is now serving a whole life jail term for the four murders and a string of rapes and sexual assaults on other men who survived.

Inquests are being held at Barking Town Hall into the deaths of the four murder victims to find out whether lives could have been saved had police acted differently.

Mr Walgate; Gabriel Kovari, 22; Daniel Whitworth, 21; and Jack Taylor, 25, were all found dead near Port’s flat during a 16-month period between June 2014 and September 2015.

The inquests continue.