Serial killer Stephen Port will spend the rest of his life behind bars for murdering four young men to satisfy his lustful obsession.

The 41-year-old was found guilty of surreptitiously giving men he met on gay dating websites fatal doses of GHB so he could rape them while they were unconscious.

He was also convicted of a string of rapes and other sexual offences against seven more men who came forward after his arrest.

Relatives of the victims cheered and clapped as Mr Justice Openshaw told an impassive Port that he would never be released.

A man in the public gallery shouted at Port: "I hope you die a long slow death you piece of shit."

Outside court, relatives of Port's final victim, who drove police to investigate the deaths, said justice had been done.

Jack Taylor's sister Donna said: "We finally have justice for Jack and the other boys.

"A sick and twisted scumbag will never be able to hurt or destroy any other family's life. Jack can finally rest in peace."

The family are planning to sue the police for failing to properly investigate the earlier deaths of Anthony Walgate, Gabriel Kovari and Daniel Whitworth.

They have said that 25-year-old forklift truck driver Mr Taylor would still be alive if they had linked the deaths and caught Port earlier.

All four deaths over 15 months bore striking similarities, but police failed to make the connection until the Taylors demanded answers.

Port had dumped the bodies in or near a graveyard within 500 metres of his flat in Barking, east London, and embarked on an elaborate cover-up, which involved planting drugs on the bodies.

He also disposed of their mobile phones, repeatedly lied to police and planted a fake suicide note in the hand of Mr Whitworth, taking the blame for the death of Mr Kovari.

Sentencing, Mr Justice Openshaw said it was for the inquiry into the police handling of the case to establish whether officers were right to take Mr Walgate's death "at face value" as they did.

On the death of Port's fourth victim 15 months later, he said: "It is not for me to say whether the seeming bizarre coincidence of these three gay young men being found dead so close together might have given rise to suspicions that these deaths were not the result of ordinary self-administered drug overdoses, but that is how their deaths, including Jack Taylor's death, was treated at the time.

"The competence and adequacy of the investigation will later be examined by others, as I have said."

He added that Port's attempt to cover up two murders with a fake suicide note was "wicked and monstrous".

In mitigation, David Etheridge QC, said that on the jury verdicts, in this period of his life, Port "descended into a vortex" in which drug taking fuelled his private life with satisfaction of his sexual desire.

"He graduated from a fetish to a fixation, from a fixation to a compulsion," he said.

The initial handling of the case has already provoked fierce criticism from friends, family and campaigners who had urged police to take their concerns seriously and act sooner.

Following Port's conviction on Wednesday, Commander Stuart Cundy said he had written a letter of condolence to the loved ones of the young men and apologised for "missed opportunities".

A total of 17 officers are being investigated over their handling of the case, seven of whom could face the sack if found to be guilty of gross misconduct.

The force is now re-examining 58 unexplained deaths involving the drug GHB from a four-year period across London to make sure that foul play has not been missed in any other cases.

The court heard Port trawled the internet for pornography involving inert young men being "raped" by older men.

The first victim, Mr Walgate, 23, was found dead in the communal hall of Port's flat in Cooke Street after he called 999 anonymously in the early hours of June 19 2014.

When police tracked him down, Port lied to officers to distance himself from the fashion student and occasional male escort.

He was later jailed for perverting the course of justice but continued to claim Mr Walgate died from taking his own drugs.

While on bail, Port murdered 22-year-old Slovakian Mr Kovari and Mr Whitworth, 21, from Gravesend within three weeks.

He dumped their bodies in Barking Abbey graveyard to be found by the same dog walker.

In Mr Whitworth's hand was a suicide note taking the blame for Mr Kovari's death, saying: "We was having some fun at a mate's place and I got carried away and gave him another shot of G."

Police treated Mr Whitworth's death "at face value" and no efforts were made to verify the sham note, which turned out to be in Port's handwriting, prosecutor Jonathan Rees QC told jurors.

Mr Taylor, 25, died within hours of hooking up with Port on Grindr in the early hours of September 13 2015.

After killing him, Port got rid of the forklift truck driver's mobile phone and deleted their communication on the gay dating app.

Just after 1pm the next day, Mr Taylor's body was found by a refuse collector with a needle and syringe in his pocket.

Initially his death was treated as "non-suspicious", the court heard.

But CCTV footage from Barking station emerged, linking him to Port, whose DNA was found on a bottle of GHB also planted in Mr Taylor's trouser pocket.

The jury convicted Port of a total of 22 offences against 11 men, including the four murders, four rapes, 10 counts of administering a substance, and four sex assaults.

Detective Chief Inspector Tim Duffield said: "These evil crimes have left entire families, a community and a nation in shock.

"I have previously said that Port is one of the most dangerous individuals I've encountered in almost 28 years of policing, and a full-life term in prison was the only appropriate punishment in the circumstances.

"All of those affected have my deepest sympathies and I hope they can find some solace from the fact that Port will spend the remainder of his life behind bars."

Human rights campaigner Peter Tatchell said: "A life sentence is entirely appropriate for these shocking, premeditated multiple murders and rapes.

"However, I am uncomfortable with whole-life sentences. If a jailed person expresses sincere remorse, has genuinely reformed and no longer poses a threat to the public, after serving 30-plus years they should be eligible for parole under licence and supervision.

"Allowing the possibility of redemption is the right thing to do."