With the stench of death closing in around them, horrified policemen searching the flat of Dennis Nilsen couldn't help but gag.
Opening up a wardrobe, they came across the first of three dead bodies - the other two were shoved into a tea chest and a chest of drawers.
Over a five-year period starting in 1978, it emerged that the deranged serial killer had murdered at least 15 young men and boys in London - each in a very similar manner.
After strangling his victims, he would typically drown them in the bath if they were still alive but unconscious, before beginning a disturbing sexual ritual with their corpses.
Nilsen's depraved games are now being retold in a new Netflix documentary Memories of a Murderer: The Nilsen Tapes, which reveals secret interview recordings of the killer drawn from more than 250 hours of cassette tapes.
Dying in 2018 as a "loner" in prison, he previously described himself as “demonic” and “the harbinger of death”. Here is the story of his tragic victims - and how he was finally brought to justice.
Plied teen with booze and slept beside corpse
Aged just 14, Stephen Holmes became the first of Nilsen's countless victims in December 1978.
When a local pub refused to serve the underage teenager on his way back from a pop concert, the killer offered to buy him booze and lured him back to his flat in Melrose Avenue, Cricklewood.
Get the biggest news delivered to your inbox. Sign up for the Mirror's free newsletters
The next morning, he strangled Stephen with a tie until he was unconscious, then drowned him in a bucket full of water.
By now, Nilsen had developed a grim obsession with the dead, even visiting morgues in his spare time.
Washing Stephen's corpse in the bath, he then placed the body on his bed and slept beside it - a grim ritual he would follow with future victims.
After pleasuring himself, he then stuffed the body underneath the floorboards of his flat, where it remained for nearly eight months.
Writing about the first murder, he admitted: "I had started down the avenue of death and possession of a new kind of flatmate."
Strangled student with headphone wire
In October 1979 a young student from Hong Kong accused Nilsen of trying to strangle him during a bondage-play session, but he decided not to press charges.
His next victim was 23-year-old Canadian student Kenneth Ockenden, whom he met in a West End pub in December 1979 and offered to take on a sight-seeing tour of the capital.
After inviting him back to his flat for a meal, Nilsen showed Kenneth his record collection.
The killer then wrapped his headphone wires around the student's neck and strangled him to death - before continuing to listen to music with the murder weapon.
Nilsen watched TV with the body for hours then put it under the floorboards, but brought it back up on multiple occasions in the next two weeks to put in his armchair while he drank.
Photographing it in suggestive positions, he once again took it to bed as part of his grim ritual.
Bathed with body of rough sleeper
Martyn Duffey, 16, was sleeping rough at Euston station when he was lured to Nilsen's home in May 1980.
Posing as a good Samaritan, the murderer offered him a bed for a night and a hot meal.
After strangling Duffey he drowned him in the sink, then bathed with the body in the bathtub and using it for sexual activity.
He initially put the body in a cupboard but decided to put it under the floorboards when he noticed signs of bloating.
Nilsen later said Martyn was the "youngest-looking I had ever seen".
'Too drunk to remember' murder
By the end of 1980, Nilsen, who would have sex with some of the corpses, had killed a further five victims - but only one of these men, William Sutherland, 26, was identified.
William - a dad to a three-year-old son - met Nilsen at the job centre where the killer worked before going to the pub with him in August 1980.
He was killed later that night, but the psychopath claimed he was too drunk to properly remember it.
Rapidly running out of storage for the bodies and with the horrific smell becoming uncontrollable, Nilsen started to cut them up.
Using butchering skills he had learned during his time with the Army's catering corps, he hacked the corpses apart on his kitchen floor with a huge knife.
Sometimes he would boil down the skulls to remove the flesh from the bone.
While he denied being a cannibal, Nilsen admitted he had considered the "culinary possibilities" of his victims, describing one part of a corpse as like "beef rump steaks".
When he had finished toying with the bodies, he buried their limbs in the garden and stuffed torsos into suitcases, storing them until he could burn them.
Burned grisly evidence in bonfire
His final victim at Melrose Avenue was Malcolm Barlow, 23, in September 1981, whom he found slumped on a wall outside his home.
Barlow was an epileptic and returned to Nilsen’s flat to thank him for calling an ambulance when he suffered a seizure, but was then strangled in his sleep and stuffed under the kitchen sink.
Forced to leave the flat by his landlord, Nilsen burned the remains of his last five Melrose Avenue victims in a bonfire in the garden behind.
He moved to a flat in Cranley Gardens, Muswell Hill, North London, where he would strangle another three men, and attempt to murder two others.
Tried to flush body parts down the toilet
In March 1982, the serial killer strangled John Howlett, 23, drowning him in the bath after three unsuccessful attempt to kill him.
Graham Allen, 27, was murdered that September - his body dissected on the kitchen floor after being left in the bathtub for three days.
Nilsen's final known victim was Stephen Sinclair, who was strangled while asleep, then bathed and laid on the bed while the murderer slept alongside the body.
With nowhere to burn the corpses in his new abode, Nilsen resorted to dismembering the three victims and boiling body parts in his kitchen so the flesh would dissolve.
He then tried to dispose of the internal organs, flesh and small bones of the men he killed by flushing them down the toilet.
This created a drainage problem that would eventually lead to his downfall.
Drains clogged with corpses
The sick necrophiliac was caught by accident after the drains became clogged with bits of rotting corpses he tried to flush away.
He and other tenants in his block of flats had complained to the landlord about the smell from the drains, so drain clearage company Dyno-Rod visited the property.
After making the horrifying discovery of bones and a flesh-like substance being eaten by rats, they called the police and Nilsen was rumbled.Video LoadingVideo UnavailableClick to playTap to playThe video will auto-play soon8CancelPlay now
A police search then turned up three men’s bodies in a wardrobe, tea chest and chest of drawers.
Nilsen claimed his memories of the attacks were vague, and that he went into a trance during the killings, saying of one victim: “In the morning he was lying there dead on one of the beds, fully clothed.
"I got the impression he wanted to go, and I must have killed him. I can’t remember strangling him.”
The killer, who seemed to have no remorse, once said: "I don’t lose sleep over what I have done or have nightmares about it."
"His crimes were extraordinary," said criminologist Professor David Wilson.
"He was a serial killer interested in power and control. Nilsen was a genuine cannibal, necrophiliac and trophy killer."
Nilsen was convicted of six counts of murder and two attempted murders on November 4 1983.
The serial killer was sentenced to life behind bars and spent the last days of his life as "a loner in prison".
He died from natural causes aged 72 after being found slumped over a toilet in 'excruciating pain' at HMP Full Sutton near York.
An inquest heard that Nilsen died after having a pulmonary embolism and bleeding in his abdominal cavity on May 12, 2018.
Got a story? Get in touch by emailing email@example.com