A Romanian couple have admitted manslaughter after two men died when they were drugged with the potent sedative gamma-butyrolactone (GBL) during sexual encounters arranged for robbery. Adina Mihai, 31, and her partner Madalin Dumitru, 30, pleaded guilty at Oxford Crown Court to two counts of manslaughter and administering poison to two further men, who cannot be named for legal reasons.
Mihai, who posed as a sex worker, and Dumitru targeted men who paid for sex, spiking their drinks with GBL to render them unconscious before stealing property. The couple, who previously lived in Birmingham and later relocated to Ilford, operated between August 2024 and July 2025, according to Thames Valley Police.
Deaths of Malcolm King and Gary Mouat
Malcolm King, 80, of Bagendon, Gloucestershire, and Gary Mouat, 36, of Banbury, Oxfordshire, lost their lives as a result of the drugging. Mr King, who was retired, wealthy and married, had contacted Mihai on 20 August 2024 and arranged to meet her at his residence that evening while his wife was absent. His body was found the next morning by his housekeeper, who also discovered an empty wine bottle and two glasses. Mr King had long-term heart conditions and was fitted with a pacemaker; cardiologists were able to establish the circumstances of his death following examination of the device.
Mr Mouat's wife and son were away on the night of 12 July last year, and he reached out to Mihai on the website Vivastreet. The pair subsequently travelled from Ilford to Mr Mouat's residence. Mr Mouat consumed wine spiked with GBL, and Mihai departed, leaving him unconscious, while she hunted for valuables to steal from the property. He was discovered the following morning lying on his lounge floor by family friends who had grown worried that he hadn't been in touch with anyone since the day before. An opened wine bottle was found close by with two glasses.
Prosecution details the couple's 'enterprise'
Julian Evans KC, prosecuting, explained that the Crown's position was that the defendants had no intention of killing their victims, but rather sought to cause harm by knocking them unconscious. "In summary, Adina Mihai and Madalin Dumitru drugged their victims via the administration of GBL, a potent drug, concealed in alcohol," he said. "They did so with a specific purpose in mind: to render their victims unconscious inside their homes in order to steal property from them."
Mr Evans stated the accused worked in tandem, fulfilling distinct functions within their "enterprise". No intimate services were actually delivered by Mihai to any of their targets, he continued. "Instead, acting under the pretence that she was there to provide sexual services for money, Mihai secretly administered GBL to each victim concealed within alcohol. Put simply, the defendants were willing to act in this way out of greed."
"Together, they no doubt drew comfort from the shared belief that they could proceed with their obviously criminal activity safe in the knowledge that their victims were highly unlikely to report what had happened to them to the police," Mr Evans added. "That confidence drew upon the obviously sensitive and embarrassing nature of the activity each victim believed they had agreed to."
Additional victims and thefts
The court was told Mihai promoted her intimate services on the website Vivastreet, and the duo would collect monetary deposits before arranging encounters. Dumitru would transport her to a location and remain outside while she conducted the sedation and robbery. Mihai would establish whether their targets were affluent and would take watches, jewellery, aftershave and money. The total value of stolen items or cash remains unknown.
Within hours of returning to Ilford from Mr Mouat's residence, a third man, referred to in court as "victim three", made contact with Mihai on Vivastreet. The defendants arrived at his home at 2.45am on July 13, with Mihai carrying a bottle of wine bought from a petrol station. Mr Evans said: "On the available evidence, there is nothing to suggest that any form of sexual activity in fact took place between victim three and Mihai inside the house." After drinking the wine laced with GBL, victim three fell into a state of unconsciousness, a state that Mihai and Dumitru anticipated, and intended. "While he was unconscious, Mihai looked around his house for property to steal. She stole a high value Rolex watch." The court was told the man had given Mihai £450, consumed some of the wine, and upon regaining consciousness discovered his watch had gone missing.
Seven days afterwards, the fourth victim, referred to as "victim four", got in touch with Mihai and she arranged to meet for £360. "On the available evidence, there is nothing to suggest that any form of sexual activity in fact took place between victim four and Mihai inside the house," Mr Evans said. "He drank some of the vodka laced with GBL that Mihai brought with her. After drinking the vodka he fell into a state of unconsciousness." Mihai stole jewellery, aftershave and documents.
The defendants, both without employment and in a relationship, had previously resided in Birmingham before relocating to Ilford. Sentencing is expected to follow after the court heard the full details of the case.
