A senior detective has apologised to the families of Barking serial killer Stephen Port’s victims, after admitting “terrible” personal errors on the case.

Det Sgt Martin O’Donnell told inquest jurors he regretted not sharing intelligence with colleagues about a previous allegation that Port plied a young man with drugs before raping him and not ensuring a search was made on the police national database about Port.

The latter meant Mr O’Donnell was unaware British Transport Police files showed Port was found at Barking Station, a short walk from his flat, with another man who was under the influence of drugs in the same month Port plied his first victim Anthony Walgate with fatal doses of GHB.

The detective also admitted not promptly looking at evidence on Port’s laptop.

When examined more than a year after he first struck, the laptop showed him searching for drug-rape pornography involving young men and boys while arranging to meet escort Mr Walgate, 23.

Mr O’Donnell, the officer in charge of progressing the investigation for the first seven months, said: “I can only apologise deeply to the families for not being able to do this (the laptop search) to the standard they expected.

“It was there on his laptop and we should have got it. We should have got it.”

He denied the accusation by Kiera Brennan, one of Mr Walgate’s friends, that police “wrote him (Mr Walgate) off” due to him being a male escort.

The inquest heard Port had initially been arrested on suspicion of raping a man in December 2012.

The case was dropped when the alleged victim withdrew his statement, despite again stating Port “forced” him to have sex after giving him drugs.

But Mr O’Donnell did not update the Crime Reporting Information System, which logs progress in an investigation for colleagues to see.

He told the hearing at Barking Town Hall: “It feels like a fairly significant mistake of mine not to include it in that document.

“It’s a terrible mistake that I did not put it in there.”

The detective’s evidence echoed the testimonies of other officers that his team had been over-worked at the time.

Mr O'Donnell said: “There was enormous pressure in the office at the time.

“We discussed what we were doing at the time as spinning plates – you would rush to one plate that seemed to be crashing down, then another plate that seemed to be crashing down.

"It was easy to miss things.”

His colleagues, Det Con Nainesh Desai and Det Con David Parish, previously told the inquest they also made mistakes over the deaths.

Mr Desai said he failed to link the first two deaths, despite both victims being young, gay men found a short distance from Port’s flat who were later found to have been drugged.

Mr Parish did not send the predator’s laptop for analysis in the days after he first struck.

Jurors are being asked to assess whether the victims’ lives could have been saved had police acted differently.

Port was initially jailed in March 2015 for lying about Mr Walgate’s death, but was released to kill for a fourth time.

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.

Port was found guilty at the Old Bailey in 2016 of the four murders and sentenced to a whole life order.

The inquest continues.