The next day, worried that he had been unable to reach Ms Geldof after repeated attempts to contact her, Mr Cohen, his mother Susan and the couple's eldest son Astala, two, arrived at the house - where he found her body, slumped on a bed in a spare room.
Phaedra was in another room in the house.
A coroner today concluded that Ms Geldof's death had been drug-related, after she took an overdose of heroin.
Geldof a long-time addict
The inquest in Gravesend was told that Ms Geldof was a heroin addict and took heroin substitute methadone in the two and a half years before her death.
Police investigating her death found an array of drugs paraphernalia at her home, including burnt spoons, 79 syringes and hundreds of pounds worth of 'importation quality' heroin.
Although she had been having drug treatment in the two years before she died, Mr Cohen found text messages in February which led him to suspect she was using drugs again.
And he confirmed to the hearing that he had witnessed her flushing drugs she had hidden in their loft down the toilet.
The inquest in Gravesend was told that there was evidence of codeine, methadone and morphine - which had come from heroin - in her blood, and that the levels were within the fatal range.
'Importation quality' heroin with a 61 per cent purity was discovered at Ms Geldof's home, as well as drug paraphernalia including burnt spoons, 79 syringes, cotton wool and a capped syringe hidden inside a box of sweets.
Husband describes finding her body
Giving evidence, musician Mr Cohen, 25, told the hearing that he had been attending rehearsals in London over the weekend of her death. When he spoke to her at 5.40pm on the Sunday she had been coherant, and he was not concerned for her well-being.
However, on the Monday morning when he was unable to reach her by telephone, he returned to their home and discovered her body.
The journalist, model and television presenter was slumped on the bed in the room the couple used when their children were sleeping, with one leg hanging down to the floor and the other tucked underneath her.
The musician confirmed that he had gone to stay with his parents in south east London with Astala and Phaedra, and that everything had seemed normal when he spoke to Ms Geldof on several occasions over the weekend.
The inquest heard that Mr Cohen's father, Keith, had seen Ms Geldof when he dropped the younger child home to her and she appeared fine, and Mr Cohen said he had last spoken to his wife at 5.40pm on Sunday April 6.
After failing to get hold of his wife the next morning, Mr Cohen and his mother returned to the property with Astala and found Ms Geldof's body.
Weekly drug tests a lie
The model had been having weekly drugs tests which she had told her husband were negative.
However, even though he had not seen her take drugs, Mr Cohen became concerned that she might be, the inquest was told.
Asked if he thought now that she may have been lying about the results, Mr Cohen, who gave evidence dressed smartly in a white shirt and black waistcoat, replied: 'Yes'.
North West Kent Coroner Roger Hatch put to Mr Cohen that Ms Geldof had been finding it difficult to come off methadone although she was reducing the dosage because she did not want to take it any more.
Asked by Mr Hatch, whether Ms Geldof had been a heroin addict, a composed Mr Cohen answered: 'Yes'.
Mr Cohen had spoken to his wife about her drugs use, and she had retrieved heroin from the loft in February this year and flushed it down the toilet, the inquest was told.
Following this, Mr Cohen would check the loft for drugs himself but found nothing, Mr Hatch said.
But Mr Cohen became aware from police inquiries following her death that drugs had been found in the house by officers trying to establish how she died.
A post-mortem examination carried out at Darent Valley Hospital found a puncture mark on the front of her right elbow and another at the front of her right thigh.
Old puncture marks were also found on her left thigh, the inquest was told.
Heroine was 'importation quality'
Police investigating Ms Geldof's death found 'importation quality' heroin stashed in a black cloth bag inside a cupboard over a bedroom door and drugs paraphernalia in the property, the inquest heard.
A capped syringe was also found hidden inside a box of sweets found by her body.
Forensic scientist Dr Peter Cain analysed the brown powder found by investigators and concluded that it was 6.91 grams of heroin with a purity of 61 per cent.
Detective Chief Inspector Paul Fotheringham, who led the investigation, told the inquest that the drugs would have been worth £350 to £550.
The officer said that it "far exceeded" the 26 per cent purity usually found at street level.
Mr Fotheringham said: "The black bag also contained 34 medical syringes, some were with needles and some without, some were sealed in original packaging and some contained traces of a brown coloured residue.
"There were also 45 packaged and sealed syringes, alcohol wipes and cotton buds."
Police also found a pair of knotted black tights under Peaches' body and two other pairs of tights with knots in them elsewhere in the property.
A burnt spoon was also found under the bed where Peaches was found dead together with cotton wool, and other burnt spoons were located throughout the house.
"Also on the bed was a small clear coloured cap thought to have come from a syringe," said Mr Fotheringham.
"Underneath the bed a dessert spoon was located with visible burn marks on the underside and a small amount of brown reside on the upper side.
"Next to the bed and within reaching distance was an open brown cardboard box containing sweets. A capped syringe was located in the box, it was noted that there was a small amount of brown fluid left in the main chamber and another small amount of residue inside the cap."
Mr Fotheringham told the inquest that forensic scientist Emma Harris found a high level of morphine in Ms Geldof's blood, suggesting she died "shortly after taking heroin" and that it was "likely" that the substance played a role in her death.
In her report, Dr Harris said: "Persons taking heroin on a regular basis develop a tolerance to the drug, and such individuals can use doses that would be toxic, or fatal, to people with no tolerance.
"However, tolerance to heroin and other opiate drugs appears to be lost fairly rapidly when users cease to use the drug, and deaths commonly occur in people who have previously been tolerant and have returned to using heroin."
Struggle to get off heroin
After hearing the evidence, Mr Hatch concluded that Ms Geldof's death was drugs-related and that heroin had played a part in her death.
He said that although she had struggled to come off methadone because of her addiction to heroin, by November 2013 Ms Geldof was found to be free of heroin and reducing her methadone.
But a message found on her phone by Mr Cohen in February this year which indicated she was using drugs again, he told the hearing.
He said that drugs paraphernalia found in her home made it clear that she was taking heroin, but that her tolerance levels had declined.
"A person with heroin addiction after reducing the amount they take, as it is apparent with Peaches by November 2013, but subsequently resumes taking heroin, the problem is that the tolerance that builds up results in an individual to use doses that are toxic or fatal to people," he said in his summing up of the inquest.
"However that tolerance appears to be lost following rehabilitation and it is common that deaths occur in people who have been previously taking and returned to using doses that are what they were used to."
Mr Hatch said that Ms Geldof had attempted to get clean, making her different from her mother , TV presenter and writer Paula Yates - who died of an accidental heroin overdose in 2000.
He continued: "It's said that the death of Peaches Geldof-Cohen is history repeating itself but this is not entirely so.
"By November last year she had ceased to take heroin as a result of the considerable treatment and counselling that she had received.
"This was a significant achievement for her but, for reasons we will never know, prior to her death she returned to taking heroin, with the fatal consequences that we have heard here today.
"I therefore find that the death of Peaches Geldof was drug-related and I express my sympathy to her family."
A police investigation into who supplied her with the drugs is on-going but as yet, no arrests have been made.
The tragedy came full circle
Ms Geldof had posted a childhood photograph of herself with her mother on her Instagram account the evening before she was found dead.
Her funeral took place took place at St Mary Magdalene and St Lawrence Church in Davington, near Faversham, where she had married Mr Cohen in 2012.
It was also where her mother married Mr Geldof in 1986 and where Ms Yates' funeral service was held.
Mr Geldof is thought to have led tributes to his daughter in front of a host of well-known personalities, including the Duchess of York, supermodel Kate Moss and former Rolling Stones bassist Bill Wyman.
The former Boomtown Rats singer has since spoken of the 'intolerable' pain he feels following his daughter's death.
In an interview with ITV's Lorraine Kelly, he said he would sometimes 'buckle' when he thought of his loss out of the blue and that it was 'still very raw'.
Ms Geldof had been a regular on the London society scene, but gave up her partying lifestyle after becoming a mother.
At the time of her death she was a columnist for Mother & Baby magazine. In her last piece, under the headline "Being a mum is the best thing in my life", she wrote she was "happier than ever".
- UK Daily Mail
